ASTM A999/A999M-23

Standard Specification for General Requirements for Alloy and Stainless Steel Pipe

SCOPE
1.1 This specification2 covers a group of general requirements that, unless otherwise specified in an individual specification, shall apply to the ASTM product specifications noted below.  
1.2 In the case of conflict between a requirement of a product specification and a requirement of this specification, the product specification shall prevail. In the case of conflict between a requirement of the product specification or a requirement of this specification and a more stringent requirement of the purchase order, the purchase order shall prevail.    
Title of Specification  
ASTM Desig-
nation3  
Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes  
A312/A312M  
Seamless and Welded Steel Pipe for Low-Temperature
Service and Other Applications with Required Notch
Toughness  
A333/A333M  
Seamless Ferritic Alloy-Steel Pipe for High Temperature
Service  
A335/A335M  
Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless
Steel Pipe for High-Temperature Service and General
Applications  
A358/A358M  
Carbon and Ferritic Alloy Steel Forged and Bored Pipe for
High-Temperature Service  
A369/A369M  
Seamless Austenitic Steel Pipe for High-Temperature
Service  
A376/A376M  
Welded Large Diameter Austenitic Steel Pipe for Corrosive
or High-Temperature Service  
A409/A409M  
Centrifugally Cast Ferritic Alloy Steel Pipe for
High-Temperature Service  
A426/A426M  
Centrifugally Cast Austenitic Steel Pipe for High-
Temperature Service  
A451/A451M  
Centrifugally Cast Iron-Chromium-Nickel High-Alloy
Tubing for Pressure Application at High
Temperatures  
A608/A608M  
Welded, Unannealed Austenitic Stainless Steel Tubular
Products  
A778/A778M  
Seamless and Welded Ferritic/Austenitic
Stainless Steel Pipe  
A790/A790M  
Single- or Double-Welded Austenitic Stainless Steel Pipe  
A813/A813M  
Cold-Worked Welded Austenitic Stainless Steel Pipe  
A814/A814M  
Centrifugally Cast Ferritic/Austenitic Stainless Steel Pipe
for Corrosive Environments  
A872/A872M  
Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric
Fusion Welded with Addition of Filler Metal  
A928/A928M  
Spray-Formed Seamless Austenitic Stainless Steel Pipes  
A943/A943M  
Spray-Formed Seamless Ferritic/Austenitic Stainless Steel Pipe  
A949/A949M  
Austenitic Chromium-Nickel-Silicon Alloy Steel Seamless
and Welded Pipe  
A954  
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. The inch-pound units apply unless the “M” designation (SI) of the product specification is specified in the order.
Note 1: The dimensionless designator NPS (nominal pipe size) is used in this standard for such traditional terms as “nominal diameter,” “size,” “nominal bore,” and “nominal size.”  
1.4 The following precautionary statement pertains only to the test method portion, Section 21, of this specification:  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Aug-2023
• ICS: 23.040.10 - Iron and steel pipes
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.10 - Stainless and Alloy Steel Tubular Products

Relations

• Refers: ASTM A335/A335M-24 - Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
• Effective Date: 01-Apr-2024
• Refers: ASTM A333/A333M-24 - Standard Specification for Seamless and Welded Steel Pipe for Low-Temperature Service and Other Applications with Required Notch Toughness
• Effective Date: 01-Apr-2024
• Refers: ASTM A369/A369M-24 - Standard Specification for Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service
• Effective Date: 01-Mar-2024
• Refers: ASTM A370-24 - Standard Test Methods and Definitions for Mechanical Testing of Steel Products
• Effective Date: 01-Mar-2024
• Refers: ASTM A409/A409M-24 - Standard Specification for Welded Large Diameter Austenitic Steel Pipe for Corrosive or High-Temperature Service
• Effective Date: 01-Mar-2024
• Refers: ASTM A312/A312M-24 - Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
• Effective Date: 01-Mar-2024
• Refers: ASTM A941-24 - Standard Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
• Effective Date: 01-Mar-2024
• Refers: ASTM A358/A358M-24 - Standard Specification for Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature Service and General Applications
• Effective Date: 01-Mar-2024
• Refers: ASTM A778/A778M-24 - Standard Specification for Welded, Unannealed Austenitic Stainless Steel Tubular Products
• Effective Date: 01-Mar-2024
• Refers: ASTM A790/A790M-24 - Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
• Effective Date: 01-Mar-2024
• Refers: ASTM A813/A813M-24 - Standard Specification for Single- or Double-Welded Austenitic Stainless Steel Pipe
• Effective Date: 01-Mar-2024
• Refers: ASTM D3951-18(2023) - Standard Practice for Commercial Packaging
• Effective Date: 01-Oct-2023
• Refers: ASTM A335/A335M-95a - Standard Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
• Effective Date: 29-Sep-2023
• Refers: ASTM A451/A451M-20 - Standard Specification for Centrifugally Cast Austenitic Steel Pipe for High-Temperature Service
• Effective Date: 01-Jul-2020
• Refers: ASTM E570-20 - Standard Practice for Flux Leakage Examination of Ferromagnetic Steel Tubular Products
• Effective Date: 01-Jun-2020

Overview

ASTM A999/A999M-23 is the internationally recognized standard specification for general requirements concerning alloy and stainless steel pipe. Developed by ASTM International, this standard outlines key specifications and requirements that apply broadly to a range of alloy and stainless steel pipe products unless otherwise specified in individual product standards. The document ensures uniformity across manufacturing and quality practices in industries utilizing seamless, welded, and cold-worked steel pipe products.

This standard serves as an umbrella for multiple specific pipe standards, ensuring that essential criteria - such as chemical composition, mechanical properties, dimensional tolerances, testing, and labeling - are consistently applied.

Key Topics

General Requirements for Steel Pipe

• Product Scope: Covers seamless, welded, and heavily cold worked alloy and stainless steel pipes, including ferritic, austenitic, duplex, and specialty alloys.
• Reference to Product Standards: Applies to a range of ASTM pipe product specifications, such as A312/A312M, A333/A333M, A335/A335M, A358/A358M, and others.
• Unit Systems: Accepts both SI (metric) and inch-pound units, but specifies that each system be used independently to prevent non-conformance.
• Ordering Requirements: Details information purchasers must specify, such as the product specification, size, grade, quantity, manufacturing method, and any special requirements.

Chemical and Mechanical Properties

• Requires strict conformance to chemical composition and tensile property requirements as established in the referenced product standards.
• Specifies testing procedures for chemical analysis, tensile strength, wall thickness, and mass per unit length.
• Mandates removal of transition materials when different steel grades are sequentially produced.

Testing and Quality Assurance

• Outlines requirements for hydrostatic and nondestructive electric testing to ensure pipe integrity.
• Provides permissible limits for mass, wall thickness, diameter, length, and straightness.
• Allows repair by welding under qualified procedures and subsequent retesting when required.

Dimensional Tolerances and Identification

• Defines permissible variations in wall thickness, inside and outside diameters, and pipe length.
• Requires appropriate marking and packaging in alignment with industry regulations and customer order specifications.

Applications

ASTM A999/A999M-23 is foundational in industries that rely on alloy and stainless steel piping for critical operations, including:

• Energy Sector: Oil and gas pipelines, refinery process piping, and power generation systems.
• Chemical Processing: Corrosive fluid handling, chemical reactors, and high-temperature service pipework.
• Construction and Infrastructure: Structural supports, water treatment plants, and pressurized applications.
• General Manufacturing: Equipment fabrication, pressure vessels, and mechanical systems.

Its use ensures end-users receive consistent, high-quality alloy and stainless steel piping that meets both industry and project-specific requirements, enhancing safety, performance, and regulatory compliance.

Related Standards

This standard underpins and refers to numerous ASTM product specifications for steel pipes, including but not limited to:

• ASTM A312/A312M: Seamless, welded, and cold-worked austenitic stainless steel pipes.
• ASTM A333/A333M: Pipes for low-temperature service.
• ASTM A335/A335M: Seamless ferritic alloy-steel pipe for high-temperature service.
• ASTM A358/A358M: Electric-fusion-welded austenitic chromium-nickel stainless steel pipe.
• ASTM A790/A790M: Seamless and welded ferritic/austenitic stainless steel pipes.
• ASTM A928/A928M: Duplex stainless steel pipe electric fusion welded with filler metal.

Additionally, the standard references key testing and terminology documents such as ASTM A370, A751, and industry guidelines from ANSI, ASME, and other technical committees.

Keywords: ASTM A999, alloy steel pipe, stainless steel pipe, general requirements for steel pipe, ASTM pipe standards, mechanical properties of steel pipe, dimensional tolerances, pipe testing standards, industry compliance, seamless welded pipe.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: A999/A999M − 23
Standard Specification for
General Requirements for Alloy and Stainless Steel Pipe
This standard is issued under the fixed designation A999/A999M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
Single- or Double-Welded Austenitic Stainless Steel Pipe A813/A813M
Cold-Worked Welded Austenitic Stainless Steel Pipe A814/A814M
1.1 This specification covers a group of general require-
Centrifugally Cast Ferritic/Austenitic Stainless Steel Pipe A872/A872M
ments that, unless otherwise specified in an individual for Corrosive Environments
Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric A928/A928M
specification, shall apply to the ASTM product specifications
Fusion Welded with Addition of Filler Metal
noted below.
Spray-Formed Seamless Austenitic Stainless Steel Pipes A943/A943M
Spray-Formed Seamless Ferritic/Austenitic Stainless Steel A949/A949M
1.2 In the case of conflict between a requirement of a
Pipe
product specification and a requirement of this specification,
Austenitic Chromium-Nickel-Silicon Alloy Steel Seamless A954
and Welded Pipe
the product specification shall prevail. In the case of conflict
between a requirement of the product specification or a 1.3 The values stated in either SI units or inch-pound units
requirement of this specification and a more stringent require-
are to be regarded separately as standard. Within the text, the
ment of the purchase order, the purchase order shall prevail. SI units are shown in brackets. The values stated in each
system may not be exact equivalents; therefore, each system
Title of Specification ASTM Desig-
nation
shall be used independently of the other. Combining values
from the two systems may result in non-conformance with the
Seamless, Welded, and Heavily Cold Worked Austenitic A312/A312M
standard. The inch-pound units apply unless the “M” designa-
Stainless Steel Pipes
Seamless and Welded Steel Pipe for Low-Temperature A333/A333M
tion (SI) of the product specification is specified in the order.
Service and Other Applications with Required Notch
Toughness
NOTE 1—The dimensionless designator NPS (nominal pipe size) is used
Seamless Ferritic Alloy-Steel Pipe for High Temperature A335/A335M
in this standard for such traditional terms as “nominal diameter,” “size,”
Service
“nominal bore,” and “nominal size.”
Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless A358/A358M
1.4 The following precautionary statement pertains only to
Steel Pipe for High-Temperature Service and General
Applications
the test method portion, Section 21, of this specification: This
Carbon and Ferritic Alloy Steel Forged and Bored Pipe for A369/A369M
standard does not purport to address all of the safety concerns,
High-Temperature Service
Seamless Austenitic Steel Pipe for High-Temperature A376/A376M if any, associated with its use. It is the responsibility of the user
Service
of this standard to establish appropriate safety, health, and
Welded Large Diameter Austenitic Steel Pipe for Corrosive A409/A409M
environmental practices and determine the applicability of
or High-Temperature Service
Centrifugally Cast Ferritic Alloy Steel Pipe for A426/A426M regulatory limitations prior to use.
High-Temperature Service
1.5 This international standard was developed in accor-
Centrifugally Cast Austenitic Steel Pipe for High- A451/A451M
dance with internationally recognized principles on standard-
Temperature Service
Centrifugally Cast Iron-Chromium-Nickel High-Alloy A608/A608M
ization established in the Decision on Principles for the
Tubing for Pressure Application at High
Development of International Standards, Guides and Recom-
Temperatures
mendations issued by the World Trade Organization Technical
Welded, Unannealed Austenitic Stainless Steel Tubular A778/A778M
Products
Barriers to Trade (TBT) Committee.
Seamless and Welded Ferritic/Austenitic A790/A790M
Stainless Steel Pipe
2. Referenced Documents
2.1 ASTM Standards:
A312/A312M Specification for Seamless, Welded, and
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
Heavily Cold Worked Austenitic Stainless Steel Pipes
A01.10 on Stainless and Alloy Steel Tubular Products.
A333/A333M Specification for Seamless and Welded Steel
Current edition approved Sept. 1, 2023. Published September 2023. Originally
approved in 1998. Last previous edition approved in 2018 as A999/A999M – 18.
DOI: 10.1520/A0999_A0999M-23.
2 4
For ASME Boiler and Pressure Vessel Code applications see related Specifi- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
cation SA 999 in Section II of that Code. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
These designations refer to the latest issue of the respective specifications. See Standards volume information, refer to the standard’s Document Summary page on
Annual Book of ASTM Standards, Vol 01.01. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A999/A999M − 23
Pipe for Low-Temperature Service and Other Applications D3951 Practice for Commercial Packaging
with Required Notch Toughness E29 Practice for Using Significant Digits in Test Data to
A335/A335M Specification for Seamless Ferritic Alloy- Determine Conformance with Specifications
Steel Pipe for High-Temperature Service E213 Practice for Ultrasonic Testing of Metal Pipe and
A358/A358M Specification for Electric-Fusion-Welded Tubing
Austenitic Chromium-Nickel Stainless Steel Pipe for E273 Practice for Ultrasonic Testing of the Weld Zone of
High-Temperature Service and General Applications Welded Pipe and Tubing
A369/A369M Specification for Carbon and Ferritic Alloy E309 Practice for Eddy Current Examination of Steel Tubu-
Steel Forged and Bored Pipe for High-Temperature Ser- lar Products Using Magnetic Saturation
vice E426 Practice for Electromagnetic (Eddy Current) Examina-
A370 Test Methods and Definitions for Mechanical Testing tion of Seamless and Welded Tubular Products, Titanium,
of Steel Products Austenitic Stainless Steel and Similar Alloys
A376/A376M Specification for Seamless Austenitic Steel E570 Practice for Flux Leakage Examination of Ferromag-
Pipe for High-Temperature Service netic Steel Tubular Products
A409/A409M Specification for Welded Large Diameter 2.2 ANSI Standards:
Austenitic Steel Pipe for Corrosive or High-Temperature
B36.10 Welded and Seamless Wrought Steel Pipe
Service B36.19 Stainless Steel Pipe
A426/A426M Specification for Centrifugally Cast Ferritic
2.3 Military Standards:
Alloy Steel Pipe for High-Temperature Service MIL-STD-163 Steel Mill Products, Preparation for Ship-
A451/A451M Specification for Centrifugally Cast Auste-
ment and Storage
nitic Steel Pipe for High-Temperature Service MIL-STD-271 Nondestructive Testing Requirements for
A608/A608M Specification for Centrifugally Cast Iron-
Metals
Chromium-Nickel High-Alloy Tubing for Pressure Appli- MIL-STD-792 Identification Marking Requirements for
cation at High Temperatures
Special Purpose Equipment
A700 Guide for Packaging, Marking, and Loading Methods
2.4 Federal Standard:
for Steel Products for Shipment
Fed. Std. No. 183 Continuous Identification Marking of Iron
A751 Test Methods and Practices for Chemical Analysis of
and Steel Products
Steel Products
2.5 Steel Structures Painting Council:
A778/A778M Specification for Welded, Unannealed Auste-
SSPC-SP6 Surface Preparation Specification No. 6 Com-
nitic Stainless Steel Tubular Products
mercial Blast Cleaning
A790/A790M Specification for Seamless and Welded
2.6 ASNT Standards:
Ferritic/Austenitic Stainless Steel Pipe
SNT-TC-1A Recommended Practice for Personnel Qualifi-
A813/A813M Specification for Single- or Double-Welded
cation and Certification in Nondestructive Testing
Austenitic Stainless Steel Pipe
3. Materials and Manufacture
A814/A814M Specification for Cold-Worked Welded Aus-
tenitic Stainless Steel Pipe
3.1 The steel shall be made by a suitable steelmaking
A872/A872M Specification for Centrifugally Cast Ferritic/
process.
Austenitic Stainless Steel Pipe for Corrosive Environ-
3.2 If secondary melting, such as electroslag remelting or
ments
vacuum remelting, is used, the heat shall be defined as all of the
A928/A928M Specification for Ferritic/Austenitic (Duplex)
ingots remelted from a single primary heat.
Stainless Steel Pipe Electric Fusion Welded with Addition
3.3 If steels of different grades are sequentially strand cast,
of Filler Metal
the resultant transition material shall be removed using an
A941 Terminology Relating to Steel, Stainless Steel, Related
established procedure that positively separates the grades.
Alloys, and Ferroalloys
A943/A943M Specification for Spray-Formed Seamless
3.4 If a specific type of melting is required by the purchaser,
Austenitic Stainless Steel Pipes
it shall be specified in the purchase order.
A949/A949M Specification for Spray-Formed Seamless
Ferritic/Austenitic Stainless Steel Pipe 4. Terminology
A954 Specification for Austenitic Chromium-Nickel-Silicon
4.1 Definitions:
Alloy Steel Seamless and Welded Pipe (Withdrawn 2005)
A994 Guide for Editorial Procedures and Form of Product
Portions of these standards appear in ASTM Book of Standards, Vol 01.01. Full
Specifications for Steel, Stainless Steel, and Related
text of these standards is available from American National Standards Institute
Alloys
(ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
A1058 Test Methods for Mechanical Testing of Steel
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
Products—Metric
dodssp.daps.dla.mil.
Available from Steel Structures Painting Council, 4400 Fifth Ave., Pittsburgh,
PA 15213.
5 9
The last approved version of this historical standard is referenced on Available from American Society for Nondestructive Testing (ASNT), P.O. Box
www.astm.org. 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
A999/A999M − 23
4.1.1 The definitions in Terminology A941, except as modi- Methods and Definitions A370, especially Annex A2 thereof,
fied in this specification or in its referenced product or Test Methods A1058.
specifications, are applicable to this specification.
7.1.1 Unless otherwise specified in the ordering
requirements, Test Methods A1058 shall apply when the metric
5. Ordering Information
version of the product specification is specified.
5.1 It is the responsibility of the purchaser to specify all
7.2 Specimens shall be tested at room temperature.
requirements that are necessary for products ordered under the
applicable product specification and this general requirements
7.3 Small or subsize specimens as described in Test Meth-
specification. Such requirements to be considered include, but ods and Definitions A370 or Test Methods A1058 may be used
are not limited to, the following:
only when there is insufficient material to prepare one of the
5.1.1 ASTM product specification and year-date, standard specimens. When using small or subsize specimens,
5.1.2 Name of product (for example, stainless steel pipe),
the largest one possible shall be used.
5.1.3 Quantity (feet, metres, or number of pieces),
5.1.4 Method of manufacture, where applicable (seamless
8. Tensile Requirements
or welded),
8.1 The material shall conform to the requirements as to
5.1.5 Specific type of melting, if required (see 3.4),
tensile properties in the applicable product specification.
5.1.6 Grade or UNS number,
5.1.7 Size (NPS and outside diameter and schedule number, 8.2 The yield strength, if specified, shall be determined
average (nominal) wall thickness (see 9.1), or minimum wall
corresponding to a permanent offset of 0.2 % of the gauge
thickness (see 9.1.1), or minimum inside diameter (see 10.1)), length or to a total extension of 0.5 % of the gauge length under
5.1.8 Length (specific or random),
load.
5.1.9 End finish,
8.3 If the percentage of elongation of any test specimen is
5.1.10 Optional requirements,
less than that specified and any part of the fracture is more than
5.1.11 Specification designation and year of issue, and
⁄4 in. [19.0 mm] from the center of the gauge length, as
5.1.12 Special requirements or any supplementary
indicated by scribe marks on the specimen before testing, a
requirements, or both.
retest shall be allowed.
6. Chemical Composition
9. Permissible Variations in Wall Thickness
6.1 Chemical Analysis—Samples for chemical analysis and
method of analysis shall be in accordance with Test Methods, 9.1 Seamless and Welded—See Table 1 for permitted varia-
tions in wall thickness except as required by 9.1.1. The
Practices, and Terminology A751.
minimum wall thickness on inspection is shown in Table X1.1.
6.2 Heat Analysis—An analysis of each heat of steel shall be
9.1.1 Minimum Wall—If the wall thickness of the pipe is
made by the steel manufacturer to determine the percentages of
specified as minimum wall in the purchase order, there shall be
the specified elements. If secondary melting processes are
no variation under the specified wall thickness. See Table 2 for
employed, the heat analysis shall be obtained from one
permitted variations in minimum wall thickness.
remelted ingot or the product of one remelted ingot of each
primary melt. The chemical composition thus determined, or
9.2 Forged and Bored—The wall thickness shall not vary
that determined from a product analysis made by the tubular 1
over that specified by more than ⁄8 in. [3.2 mm]. There shall be
product manufacturer shall conform to the requirements speci-
no variation under the specified wall thickness.
fied.
9.3 Cast—The wall thickness shall not vary over that
6.2.1 For steels ordered under product specifications refer-
specified by more than ⁄16 in. [1.6 mm]. There shall be no
encing this specification of general requirements, the steel shall
variation under the specified wall thickness.
not contain an unspecified element, other than nitrogen for
stainless steels, for the ordered grade to the extent that the steel
conforms to the requirements of another grade for which that
element is a specified element having a required minimum
TABLE 1 Permitted Variations in Wall Thickness
content. For this requirement, a grade is defined as an alloy
described individually and identified by its own UNS designa- Tolerance % from Nominal
NPS [DN] Designator Over Under
tion in a table of chemical requirements within any specifica-
1 1
⁄8 [DN 6] to 2- ⁄2 [DN 65] incl., all t/D 20.0 12.5
tion listed within the scope as being covered by this specifi-
ratios
cation. 3 [DN 80] to 18 [DN 450] incl., t/D up to 22.5 12.5
5% incl.
6.3 Product Analysis—Product analysis requirements and
3 [DN 80] to 18 [DN 450] incl., t/D > 5% 15.0 12.5
incl.
options, if any, shall be as contained in the applicable product
20 [DN 500] and larger, welded, all t/D 17.5 12.5
specification.
ratios
20 [DN 500] and larger, seamless, t/D up 22.5 12.5
7. Mechanical Properties
to 5 % incl.
20 [DN 500] and larger, seamless, t/D > 15.0 12.5
7.1 Method of Mechanical Tests—The specimens and me-
5%
chanical tests required shall be in accordance with Test
A999/A999M − 23
TABLE 2 Permitted Variations in Wall Thickness for Minimum
12.2 Forged and Bored, Cast, and Cast Cold-Wrought—If
Wall
specific cut lengths are ordered, no length of pipe shall be
Tolerance % from Specified Minimum 1
under the length specified or more than ⁄8 in. [3 mm] over that
NPS [DN] Designator Over Under
specified.
1 1
⁄8 [DN 6] to 2- ⁄2 [DN 65] incl., all t/D 32.5 0
ratios
12.3 For pipe ordered to random lengths, the lengths and
3 [DN 80] to 18 [DN 450] incl., t/D up to 35.0 0
variations shall be agreed upon between the manufacturer and
5% incl.
3 [DN 80] to 18 [DN 450] incl., t/D > 5% 27.5 0
purchaser.
incl.
12.4 No girth welds are permitted unless agreed upon by the
20 [DN 500] and larger, welded, all t/D 30.0 0
ratios
manufacturer and purchaser.
20 [DN 500] and larger, seamless, t/D up 35.0 0
to 5 % incl.
13. Other Sizes
20 [DN 500] and larger, seamless, t/D > 27.5 0
5%
13.1 A system of standard pipe sizes has been approved by
the American National Standards Institute as ANSI B36.10 and
B36.19. The standard sizes do not prohibit the production and
10. Permissible Variations in Inside Diameter
use of other sizes of pipe produced to the various product
10.1 Forged and Bored, and Cast—The inside diameter
specifications referenced in 1.1.
shall not vary under that specified by more than ⁄16 in. [1.6
mm]. There shall be no variation over the specified inside 14. Ends
diameter.
14.1 Unless otherwise specified, the pipe shall be furnished
with plain ends. All burrs at the ends of the pipe shall be
11. Permissible Variation in Outside Diameter
removed.
11.1 Variations in outside diameter, unless otherwise agreed
upon, shall not exceed the limits given in Table 3. The
15. Straightness
tolerances for outside diameter include ovality, except as
15.1 The finished pipe shall be reasonably straight.
provided for in 11.2 and 11.2.1. (See Note 2.)
15.2 For metal-arc welded pipe, the maximum deviation
11.2 For thin-wall pipe, defined as pipe having a wall
from a 10-ft [3.0-m] straightedge placed so that both ends are
thickness of 3 % or less of the specified outside diameter, the
in contact with the pipe shall be ⁄8 in. [3.2 mm]. For metal-arc
diameter tolerance of Table 3 is applicable only to the mean of
welded pipe with lengths shorter than 10 ft [3.0 m], this
the extreme (maximum and minimum) outside diameter read-
maximum deviation shall be prorated with respect to the ratio
ings in any one cross-section.
of the actual length to 10 ft [3.0 m].
11.2.1 For thin-wall pipe, the difference in extreme outside
readings (ovality) in any one cross-section shall not exceed
16. Repair by Welding
1.5 % of the specified outside diameter.
16.1 Repair by welding of defects in seamless pipe (includ-
NOTE 2—Thin-wall pipe usually develops significant ovality (out-of-
ing centrifugally cast pipe and forged and bored pipe) and of
roundness) during final annealing, straightening, or both. The diameter
plate defects in welded pipe and, if specifically stated by the
tolerances given in Table 3 are usually not sufficient to provide for
additional ovality expected in thin-wall pipe. applicable product specification, weld seam defects in welded
pipe shall be permitted subject to the approval of the purchaser
12. Permissible Variations in Length
and with the further understanding that the composition of the
12.1 Seamless and Welded (No Filler Metal Added)—If deposited filler metal shall be suitable for the composition
specific cut lengths of 24 ft [7.3 m] or less are ordered, no being welded. Defects shall be thoroughly chipped or ground
length of pipe shall be under the length specified or more than out before welding and each repaired length shall be reheat
⁄4 in. [6 mm] over that specified. treated or stress relieved as required by the applicable product
12.1.1 Permissible variations in length for lengths greater specification. Each length of repaired pipe shall be nondestruc-
than 24 ft [7.3 m] shall be subject to agreement between the tively tested as required by the applicable product specifica-
manufacturer and purchaser. tion.
TABLE 3 Permissible Variations in Outside Diameter
NPS Permissible Variations in Outside Diameter DN Designator Permissible Variations in Outside
Designator Diameter
Over Under Over Under
in. in. [mm] [mm]
1 1 1 1
⁄8 –1 ⁄2, incl ⁄64 (0.015) ⁄32 (0.031) [6–40], incl [0.4] [0.8]
1 1 1
Over 1 ⁄2 to 4, incl ⁄32 (0.031) ⁄32 (0.031) Over [40 to 100] [0.8] [0.8]
1 1
Over 4 to 8, incl ⁄16 (0.062) ⁄32 (0.031) Over [100 to 200] [1.6] [0.8]
3 1
Over 8 to 18, incl ⁄32 (0.093) ⁄32 (0.031) Over [200 to 450] [2.4] [0.8]
1 1
Over 18 to 26, incl ⁄8 (0.125) ⁄32 (0.031) Over [450 to 650] [3.2] [0.8]
5 1
Over 26 to 34, incl ⁄32 (0.156) ⁄32 (0.031) Over [650 to 850] [4.0] [0.8]
3 1
Over 34 to 48, incl ⁄16 (0.187) ⁄32 (0.031) Over [850 to 1200] [4.8] [0.8]
A999/A999M − 23
16.2 Repair welding shall be performed using procedures
e = deformation per unit length (constant for a given grade
and welders or welding operators that have been qualified in
of steel, 0.07 for medium carbon steel (maximum
accordance with the ASME Boiler and Pressure Vessel Code,
specified carbon 0.19 % or greater), 0.08 for ferritic
Section IX.
alloy steel, 0.09 for austenitic steel, 0.09 for duplex
(ferritic/austenitic) stainless steel, and 0.09 for low-
17. Retests
carbon steel (maximum specified carbon 0.18 % or
less)).
17.1 If the results of the qualification tests of any lot do not
conform to the requirements specified in the applicable product
During the second step, which is a test for soundness, the
specification, retests are permitted on additional lengths of pipe
flattening shall be continued until the specimen breaks or the
of double the original number from the same lot, each of which
opposite walls of the specimen meet.
shall conform to the requirements specified. Only one retest of
20.2 Welded Pipe—A section of welded pipe not less than 4
any lot is permitted. Nonconformance of the retest is cause for
in. [100 mm] in length shall be flattened cold between parallel
the rejection of the lot.
plates in two steps. The weld shall be placed at 90° from the
17.2 Any individual length of pipe that meets the test
direction of the applied force (at the point of maximum
requirements is acceptable. It is permitted to retest individual
bending). During the first step, which is a test for ductility, no
lengths that do not conform to the test requirements, provided
cracks or breaks on the inside or outside surfaces, except as
that the reason for nonconformance is established and the
provided for in 20.3.4, shall occur before the distance between
nonconforming portion is removed.
the plates is less than the value of H calculated by Eq 1. During
the second step, which is a test for soundness, the flattening
18. Retreatment
shall be continued until the specimen breaks or the opposite
18.1 If individual lengths of pipe selected to represent any walls of the specimen meet.
lot fail to conform to the test requirements, the lot represented
20.3 Seamless, Centrifugally Cast, and Welded Pipe:
may be reheat treated and resubmitted for test. The manufac-
20.3.1 Evidence of laminated or defective material or weld
turer may reheat treat the pipe, but not more than twice, except
that is revealed at any time during the entire flattening test shall
with the approval of the purchaser.
be cause for rejection.
20.3.2 Surface imperfections not evident in the test speci-
19. Test Specimens
men before flattening, but revealed during the first step of the
19.1 Test specimens shall be taken from the ends of finished
flattening test, shall be judged in accordance with the finish
pipe prior to any forming operations, or being cut to length.
requirements.
19.2 Specimens cut either longitudinally or transversely
20.3.3 Superficial ruptures resulting from surface imperfec-
shall be acceptable for the tension test.
tions shall not be a cause for rejection.
19.3 If any test specimen shows flaws or defective
20.3.4 When low D-to-t ratio tubular products are tested,
machining, the specimen may be discarded and another sub-
because the strain imposed due to geometry is unreasonably
stituted.
high on the inside surface at the six and twelve o’clock
locations, cracks at these locations shall not be cause for
20. Flattening Test Requirements
rejection if the D-to-t ratio is less than 10.
20.1 Seamless and Centrifugally Cast Pipe—A section of
21. Nondestructive Test Requirements
pipe not less than 2 ⁄2 in. [60 mm] in length shall be flattened
cold between parallel plates in two steps. During the first step,
21.1 If required by the applicable product specification or
which is a test for ductility, no cracks or breaks on the inside,
the purchase order, the pipe shall be tested by the hydrostatic
outside, or end surfaces, except as allowed by 20.3.4, shall
test (see 21.2) or by the nondestructive electric test (see 21.3).
occur before the distance between the plates is less than the
21.2 Hydrostatic Test:
value of H calculated as follows:
21.2.1 Except as allowed by 21.2.2 and 21.2.3, each length
H 5 ~1 1 e!t⁄~e 1 t ⁄ D! (1)
of pipe shall be tested by the manufacturer to a hydrostatic
where:
pressure that will produce in the pipe wall a stress not less than
H = distance between flattening plates, in. [mm], 60 % of the specified minimum yield strength for ferritic alloy
t = specified wall thickness, in. [mm],
steel and stainless steel pipe, or 50 % of the specified minimum
D = specified outside diameter, outside diameter correspond-
yield strength for austenitic alloy and stainless steel pipe and
ing to specified ANSI pipe size, or outside diameter
for ferritic/austenitic stainless steel pipe. The test pressure or
calculated by adding 2t (as defined above) to the
stress shall be determined using the following equation:
specified inside diameter in. [mm], and
P 5 2St⁄D or S 5 PD⁄2t (2)
A999/A999M − 23
where: 21.3.2.3 The eddy-current testing (ET) referenced in this
specification, (see Practices E426 and E309), has the capability
P = hydrostatic test pressure in psi [MPa],
of detecting significant imperfections, especially of the short
S = pipe wall stress in psi or [MPa],
t = specified wall thickness, nominal wall thickness accord- abrupt type. The sensitivity of this test decreases with wall
thickness over 0.250 in. (6.4 mm).
ing to specified ANSI schedule number, or 1.143 times
the specified minimum wall thickness, in. [mm], and
21.3.2.4 The flux leakage examination referred to in this
D = specified outside diameter, outside diameter correspond-
specification is capable of detecting the presence and location
ing to specified ANSI pipe size, or outside diameter
of significant longitudinally or transversely oriented imperfec-
calculated by adding 2t (as defined above) to the
tions; however, sensitivity of the test to various types of
specified inside diameter, in. [mm].
imperfections is affected by the calibration, and different
techniques should be employed to detect differently oriented
21.2.1.1 The hydrostatic test pressure determined by Eq 2
imperfections.
shall be rounded to the nearest 50 psi [0.5 MPa] for pressures
21.3.2.5 A purchaser interested in ascertaining the nature
below 1000 psi [7 MPa], and to the nearest 100 psi [1 MPa] for
(type, size, location, and orientation) of imperfections that can
pressures 1000 psi [7 MPa] and above. The hydrostatic test
be detected in the specific application of these examinations
may be performed prior to cutting to final length, or prior to
should discuss this with the manufacturer of the tubular
upsetting, swaging, expanding, bending, or other forming
product.
operations.
21.3.3 Time of Examination:
21.2.2 Regardless of pipe-wall stress-level determined by
21.3.3.1 Nondestructive testing for specification acceptance
Eq 2, the minimum hydrostatic test pressure required to satisfy
shall be performed after all mechanical processing, heat
these requirements need not exceed 2500 psi [17.0 MPa] for
treatments, and straightening operations. This requirement
outside diameters (see D in 21.2) of 3.5 in. [88.9 mm] or less,
does not preclude additional testing at earlier stages in the
or 2800 psi [19.0 MPa] for outside diameters over 3.5 in. [88.9
processing.
mm]. This does not prohibit testing at higher pressures at the
option of the manufacturer or as allowed by 21.2.3. 21.3.4 Surface Condition:
21.2.3 With concurrence of the manufacturer, a minimum 21.3.4.1 All surfaces shall be free of scale, dirt, grease,
hydrostatic test pressure in excess of the requirements of 21.1
paint, and other foreign material that could interfere with
or 21.
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: A999/A999M − 18 A999/A999M − 23
Standard Specification for
General Requirements for Alloy and Stainless Steel Pipe
This standard is issued under the fixed designation A999/A999M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification covers a group of general requirements that, unless otherwise specified in an individual specification, shall
apply to the ASTM product specifications noted below.
1.2 In the case of conflict between a requirement of a product specification and a requirement of this specification, the product
specification shall prevail. In the case of conflict between a requirement of the product specification or a requirement of this
specification and a more stringent requirement of the purchase order, the purchase order shall prevail.
Title of Specification ASTM Desig-
nation
Seamless, Welded, and Heavily Cold Worked Austenitic A312/A312M
Stainless Steel Pipes
Seamless and Welded Steel Pipe for Low-Temperature A333/A333M
Service and Other Applications with Required Notch
Toughness
Seamless Ferritic Alloy-Steel Pipe for High Temperature A335/A335M
Service
Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless A358/A358M
Steel Pipe for High-Temperature Service and General
Applications
Carbon and Ferritic Alloy Steel Forged and Bored Pipe for A369/A369M
High-Temperature Service
Seamless Austenitic Steel Pipe for High-Temperature A376/A376M
Service
Welded Large Diameter Austenitic Steel Pipe for Corrosive A409/A409M
or High-Temperature Service
Centrifugally Cast Ferritic Alloy Steel Pipe for A426/A426M
High-Temperature Service
Centrifugally Cast Austenitic Steel Pipe for High- A451/A451M
Temperature Service
Centrifugally Cast Iron-Chromium-Nickel High-Alloy A608/A608M
Tubing for Pressure Application at High
Temperatures
Welded, Unannealed Austenitic Stainless Steel Tubular A778/A778M
Products
Seamless and Welded Ferritic/Austenitic A790/A790M
Stainless Steel Pipe
Single- or Double-Welded Austenitic Stainless Steel Pipe A813/A813M
Cold-Worked Welded Austenitic Stainless Steel Pipe A814/A814M
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.10
on Stainless and Alloy Steel Tubular Products.
Current edition approved March 1, 2018Sept. 1, 2023. Published March 2018September 2023. Originally approved in 1998. Last previous edition approved in 20172018
as A999/A999M – 17.A999/A999M – 18. DOI: 10.1520/A0999_A0999M-18.10.1520/A0999_A0999M-23.
For ASME Boiler and Pressure Vessel Code applications see related Specification SA 999 in Section II of that Code.
These designations refer to the latest issue of the respective specifications. See Annual Book of ASTM Standards, Vol 01.01.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A999/A999M − 23
Centrifugally Cast Ferritic/Austenitic Stainless Steel Pipe A872/A872M
for Corrosive Environments
Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric A928/A928M
Fusion Welded with Addition of Filler Metal
Spray-Formed Seamless Austenitic Stainless Steel Pipes A943/A943M
Spray-Formed Seamless Ferritic/Austenitic Stainless Steel A949/A949M
Pipe
Austenitic Chromium-Nickel-Silicon Alloy Steel Seamless A954
and Welded Pipe
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units
are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used
independently of the other. Combining values from the two systems may result in non-conformance with the standard. The
inch-pound units apply unless the “M” designation (SI) of the product specification is specified in the order.
NOTE 1—The dimensionless designator NPS (nominal pipe size) is used in this standard for such traditional terms as “nominal diameter,” “size,” “nominal
bore,” and “nominal size.”
1.4 The following precautionary statement pertains only to the test method portion, Section 2221, of this specification: This
standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory
limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A312/A312M Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
A333/A333M Specification for Seamless and Welded Steel Pipe for Low-Temperature Service and Other Applications with
Required Notch Toughness
A335/A335M Specification for Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service
A358/A358M Specification for Electric-Fusion-Welded Austenitic Chromium-Nickel Stainless Steel Pipe for High-Temperature
Service and General Applications
A369/A369M Specification for Carbon and Ferritic Alloy Steel Forged and Bored Pipe for High-Temperature Service
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A376/A376M Specification for Seamless Austenitic Steel Pipe for High-Temperature Service
A409/A409M Specification for Welded Large Diameter Austenitic Steel Pipe for Corrosive or High-Temperature Service
A426/A426M Specification for Centrifugally Cast Ferritic Alloy Steel Pipe for High-Temperature Service
A451/A451M Specification for Centrifugally Cast Austenitic Steel Pipe for High-Temperature Service
A608/A608M Specification for Centrifugally Cast Iron-Chromium-Nickel High-Alloy Tubing for Pressure Application at High
Temperatures
A700 Guide for Packaging, Marking, and Loading Methods for Steel Products for Shipment
A751 Test Methods and Practices for Chemical Analysis of Steel Products
A778/A778M Specification for Welded, Unannealed Austenitic Stainless Steel Tubular Products
A790/A790M Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
A813/A813M Specification for Single- or Double-Welded Austenitic Stainless Steel Pipe
A814/A814M Specification for Cold-Worked Welded Austenitic Stainless Steel Pipe
A872/A872M Specification for Centrifugally Cast Ferritic/Austenitic Stainless Steel Pipe for Corrosive Environments
A928/A928M Specification for Ferritic/Austenitic (Duplex) Stainless Steel Pipe Electric Fusion Welded with Addition of Filler
Metal
A941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys
A943/A943M Specification for Spray-Formed Seamless Austenitic Stainless Steel Pipes
A949/A949M Specification for Spray-Formed Seamless Ferritic/Austenitic Stainless Steel Pipe
A954 Specification for Austenitic Chromium-Nickel-Silicon Alloy Steel Seamless and Welded Pipe (Withdrawn 2005)
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
A999/A999M − 23
A994 Guide for Editorial Procedures and Form of Product Specifications for Steel, Stainless Steel, and Related Alloys
A1058 Test Methods for Mechanical Testing of Steel Products—Metric
D3951 Practice for Commercial Packaging
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E213 Practice for Ultrasonic Testing of Metal Pipe and Tubing
E273 Practice for Ultrasonic Testing of the Weld Zone of Welded Pipe and Tubing
E309 Practice for Eddy Current Examination of Steel Tubular Products Using Magnetic Saturation
E426 Practice for Electromagnetic (Eddy Current) Examination of Seamless and Welded Tubular Products, Titanium, Austenitic
Stainless Steel and Similar Alloys
E570 Practice for Flux Leakage Examination of Ferromagnetic Steel Tubular Products
2.2 ANSI Standards:
B36.10 Welded and Seamless Wrought Steel Pipe
B36.19 Stainless Steel Pipe
2.3 Military Standards:
MIL-STD-163 Steel Mill Products, Preparation for Shipment and Storage
MIL-STD-271 Nondestructive Testing Requirements for Metals
MIL-STD-792 Identification Marking Requirements for Special Purpose Equipment
2.4 Federal Standard:
Fed. Std. No. 183 Continuous Identification Marking of Iron and Steel Products
2.5 Steel Structures Painting Council:
SSPC-SP6 Surface Preparation Specification No. 6 Commercial Blast Cleaning
2.6 ASNT Standards:
SNT-TC-1A Recommended Practice for Personnel Qualification and Certification in Nondestructive Testing
3. Materials and Manufacture
3.1 The steel shall be made by a suitable steelmaking process.
3.2 If secondary melting, such as electroslag remelting or vacuum remelting, is used, the heat shall be defined as all of the ingots
remelted from a single primary heat.
3.3 If steels of different grades are sequentially strand cast, the resultant transition material shall be removed using an established
procedure that positively separates the grades.
3.4 If a specific type of melting is required by the purchaser, it shall be specified in the purchase order.
4. Terminology
4.1 Definitions:
4.1.1 The definitions in Terminology A941, except as modified in this specification or in its referenced product specifications, are
applicable to this specification.
5. Ordering Information
5.1 It is the responsibility of the purchaser to specify all requirements that are necessary for products ordered under the applicable
product specification and this general requirements specification. Such requirements to be considered include, but are not limited
to, the following:
5.1.1 ASTM product specification and year-date,
5.1.2 Name of product (for example, stainless steel pipe),
Portions of these standards appear in ASTM Book of Standards, Vol 01.01. Full text of these standards is available from American National Standards Institute (ANSI),
25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://dodssp.daps.dla.mil.
Available from Steel Structures Painting Council, 4400 Fifth Ave., Pittsburgh, PA 15213.
Available from American Society for Nondestructive Testing (ASNT), P.O. Box 28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http://www.asnt.org.
A999/A999M − 23
5.1.3 Quantity (feet, metres, or number of pieces),
5.1.4 Method of manufacture, where applicable (seamless or welded),
5.1.5 Specific type of melting, if required (see 3.4),
5.1.6 Grade or UNS number,
5.1.7 Size (NPS and outside diameter and schedule number, average (nominal) wall thickness (see 9.1 and 10.1), or minimum wall
thickness (see 9.2 and 10.1.19.1.1), or minimum inside diameter (see 11.110.1)),
5.1.8 Length (specific or random),
5.1.9 End finish,
5.1.10 Optional requirements,
5.1.11 Specification designation and year of issue, and
5.1.12 Special requirements or any supplementary requirements, or both.
6. Chemical Composition
6.1 Chemical Analysis—Samples for chemical analysis and method of analysis shall be in accordance with Test Methods,
Practices, and Terminology A751.
6.2 Heat Analysis—An analysis of each heat of steel shall be made by the steel manufacturer to determine the percentages of the
specified elements. If secondary melting processes are employed, the heat analysis shall be obtained from one remelted ingot or
the product of one remelted ingot of each primary melt. The chemical composition thus determined, or that determined from a
product analysis made by the tubular product manufacturer shall conform to the requirements specified.
6.2.1 For steels ordered under product specifications referencing this specification of general requirements, the steel shall not
contain an unspecified element, other than nitrogen for stainless steels, for the ordered grade to the extent that the steel conforms
to the requirements of another grade for which that element is a specified element having a required minimum content. For this
requirement, a grade is defined as an alloy described individually and identified by its own UNS designation in a table of chemical
requirements within any specification listed within the scope as being covered by this specification.
6.3 Product Analysis—Product analysis requirements and options, if any, shall be as contained in the applicable product
specification.
7. Mechanical Properties
7.1 Method of Mechanical Tests—The specimens and mechanical tests required shall be in accordance with Test Methods and
Definitions A370, especially Annex A2 thereof, or Test Methods A1058.
7.1.1 Unless otherwise specified in the ordering requirements, Test Methods A1058 shall apply when the metric version of the
product specification is specified.
7.2 Specimens shall be tested at room temperature.
7.3 Small or subsize specimens as described in Test Methods and Definitions A370 or Test Methods A1058 may be used only
when there is insufficient material to prepare one of the standard specimens. When using small or subsize specimens, the largest
one possible shall be used.
A999/A999M − 23
8. Tensile Requirements
8.1 The material shall conform to the requirements as to tensile properties in the applicable product specification.
8.2 The yield strength, if specified, shall be determined corresponding to a permanent offset of 0.2 % of the gauge length or to
a total extension of 0.5 % of the gauge length under load.
8.3 If the percentage of elongation of any test specimen is less than that specified and any part of the fracture is more than ⁄4 in.
[19.0 mm] from the center of the gauge length, as indicated by scribe marks on the specimen before testing, a retest shall be
allowed.
9. Permissible Variation in Mass for Seamless Pipe
9.1 Except as allowed by 9.2, the mass of any length of seamless pipe in sizes NPS 12 and smaller shall not vary more than 10 %
over or more than 3.5 % under that specified. For pipe in sizes larger than NPS 12, the mass of any length of pipe shall not vary
more than 10 % over or more than 5 % under that specified. Unless otherwise specified, the mass of lengths of pipe in sizes NPS
4 and smaller shall be determined separately or in convenient lots; the mass of lengths of pipe in sizes larger than NPS 4 shall be
determined separately.
9.2 Minimum Wall—If the wall thickness of the pipe is specified as minimum wall in the purchase order, the mass of any length
of seamless pipe shall not vary more than 16 % over that calculated in accordance with 14.3. Unless otherwise specified, the mass
of pipe in sizes NPS 4 and smaller shall be determined separately or in convenient lots; the mass of pipe in sizes larger than NPS
4 shall be determined separately.
9.3 The specified mass of pipe shall be determined by multiplying its specified or calculated mass per unit length (see 14.3) by
its measured length.
9. Permissible Variations in Wall Thickness
9.1 Seamless and Welded—Except asSee Table 1 required byfor permitted 10.1.1, the minimum wall thickness at any
pointvariations in wall thickness except as required by 9.1.1shall not be more than 12.5 % under the nominal wall thickness
specified. . The minimum wall thickness on inspection is shown in Table X1.1.
9.1.1 Minimum Wall—If the wall thickness of the pipe is specified as minimum wall in the purchase order, there shall be no
variation under the specified wall thickness. See Table 2 for permitted variations in minimum wall thickness.
9.2 Forged and Bored—The wall thickness shall not vary over that specified by more than ⁄8 in. [3.2 mm]. There shall be no
variation under the specified wall thickness.
9.3 Cast—The wall thickness shall not vary over that specified by more than ⁄16 in. [1.6 mm]. There shall be no variation under
the specified wall thickness.
TABLE 1 Permitted Variations in Wall Thickness
Tolerance % from Nominal
NPS [DN] Designator Over Under
1 1
⁄8 [DN 6] to 2- ⁄2 [DN 65] incl., all t/D 20.0 12.5
ratios
3 [DN 80] to 18 [DN 450] incl., t/D up to 22.5 12.5
5% incl.
3 [DN 80] to 18 [DN 450] incl., t/D > 5% 15.0 12.5
incl.
20 [DN 500] and larger, welded, all t/D 17.5 12.5
ratios
20 [DN 500] and larger, seamless, t/D up 22.5 12.5
to 5 % incl.
20 [DN 500] and larger, seamless, t/D > 15.0 12.5
5%
A999/A999M − 23
TABLE 2 Permitted Variations in Wall Thickness for Minimum
Wall
Tolerance % from Specified Minimum
NPS [DN] Designator Over Under
1 1
⁄8 [DN 6] to 2- ⁄2 [DN 65] incl., all t/D 32.5 0
ratios
3 [DN 80] to 18 [DN 450] incl., t/D up to 35.0 0
5% incl.
3 [DN 80] to 18 [DN 450] incl., t/D > 5% 27.5 0
incl.
20 [DN 500] and larger, welded, all t/D 30.0 0
ratios
20 [DN 500] and larger, seamless, t/D up 35.0 0
to 5 % incl.
20 [DN 500] and larger, seamless, t/D > 27.5 0
5%
10. Permissible Variations in Inside Diameter
10.1 Forged and Bored, and Cast—The inside diameter shall not vary under that specified by more than ⁄16 in. [1.6 mm]. There
shall be no variation over the specified inside diameter.
11. Permissible Variation in Outside Diameter
11.1 Variations in outside diameter, unless otherwise agreed upon, shall not exceed the limits given in Table 13. The tolerances
for outside diameter include ovality, except as provided for in 12.211.2 and 12.2.111.2.1. (See Note 2.)
11.2 For thin-wall pipe, defined as pipe having a wall thickness of 3 % or less of the specified outside diameter, the diameter
tolerance of Table 13 is applicable only to the mean of the extreme (maximum and minimum) outside diameter readings in any
one cross-section.
11.2.1 For thin-wall pipe, the difference in extreme outside readings (ovality) in any one cross-section shall not exceed 1.5 % of
the specified outside diameter.
NOTE 2—Thin-wall pipe usually develops significant ovality (out-of-roundness) during final annealing, straightening, or both. The diameter tolerances
given in Table 13 are usually not sufficient to provide for additional ovality expected in thin-wall pipe.
12. Permissible Variations in Length
12.1 Seamless and Welded (No Filler Metal Added)—If specific cut lengths of 24 ft [7.3 m] or less are ordered, no length of pipe
shall be under the length specified or more than ⁄4 in. [6 mm] over that specified.
12.1.1 Permissible variations in length for lengths greater than 24 ft [7.3 m] shall be subject to agreement between the
manufacturer and purchaser.
12.2 Forged and Bored, Cast, and Cast Cold-Wrought—If specific cut lengths are ordered, no length of pipe shall be under the
length specified or more than ⁄8 in. [3 mm] over that specified.
TABLE 13 Permissible Variations in Outside Diameter
NPS Permissible Variations in Outside Diameter DN Designator Permissible Variations in Outside
Designator Diameter
Over Under Over Under
in. in. [mm] [mm]
1 1 1 1
⁄8 –1 ⁄2, incl ⁄64 (0.015) ⁄32 (0.031) [6–40], incl [0.4] [0.8]
1 1 1
Over 1 ⁄2 to 4, incl ⁄32 (0.031) ⁄32 (0.031) Over [40 to 100] [0.8] [0.8]
1 1
Over 4 to 8, incl ⁄16 (0.062) ⁄32 (0.031) Over [100 to 200] [1.6] [0.8]
3 1
Over 8 to 18, incl ⁄32 (0.093) ⁄32 (0.031) Over [200 to 450] [2.4] [0.8]
1 1
Over 18 to 26, incl ⁄8 (0.125) ⁄32 (0.031) Over [450 to 650] [3.2] [0.8]
5 1
Over 26 to 34, incl ⁄32 (0.156) ⁄32 (0.031) Over [650 to 850] [4.0] [0.8]
3 1
Over 34 to 48, incl ⁄16 (0.187) ⁄32 (0.031) Over [850 to 1200] [4.8] [0.8]
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12.3 For pipe ordered to random lengths, the lengths and variations shall be agreed upon between the manufacturer and purchaser.
12.4 No girth welds are permitted unless agreed upon by the manufacturer and purchaser.
13. Mass per Unit Length Other Sizes
13.1 A system of standard pipe sizes has been approved by the American National Standards Institute as ANSI B36.10 and B36.19.
The standard sizes do not prohibit the production and use of other sizes of pipe produced to the various product specifications
referenced in 1.1. (See Note 3.)
14.2 For nonstandard sizes of pipe, the calculated mass per unit length shall be determined using the following equation:
M 5 C~D 2 t!t (1)
where:
C = 10.69 [0.0246615],
M = mass per unit length, lb /ft [kg/m],
m
D = specified or calculated (from specified inside diameter and wall thickness) outside diameter, in. [mm], and
t = specified wall thickness, in. (to 3 decimal places) [mm to 2 decimal places].
14.3 When minimum wall thickness is specified in the purchase order, the calculated mass per unit length shall be determined
using Eq 1, obtaining from Table X1.1 the nominal wall thickness, t, corresponding to that minimum wall.
NOTE 3—The mass per unit length values given in the American National Standards and the calculated masses per unit length determined using Eq 1 are
based upon carbon steel pipe. The mass per unit length of pipe made of ferritic stainless steels may be up to about 5 % less, and that made of austenitic
stainless steel up to about 2 % greater, than the values given.
14. Ends
14.1 Unless otherwise specified, the pipe shall be furnished with plain ends. All burrs at the ends of the pipe shall be removed.
15. Straightness
15.1 The finished pipe shall be reasonably straight.
15.2 For metal-arc welded pipe, the maximum deviation from a 10-ft [3.0-m] straightedge placed so that both ends are in contact
with the pipe shall be ⁄8 in. [3.2 mm]. For metal-arc welded pipe with lengths shorter than 10 ft [3.0 m], this maximum deviation
shall be prorated with respect to the ratio of the actual length to 10 ft [3.0 m].
16. Repair by Welding
16.1 Repair by welding of defects in seamless pipe (including centrifugally cast pipe and forged and bored pipe) and of plate
defects in welded pipe and, if specifically stated by the applicable product specification, weld seam defects in welded pipe shall
be permitted subject to the approval of the purchaser and with the further understanding that the composition of the deposited filler
metal shall be suitable for the composition being welded. Defects shall be thoroughly chipped or ground out before welding and
each repaired length shall be reheat treated or stress relieved as required by the applicable product specification. Each length of
repaired pipe shall be nondestructively tested as required by the applicable product specification.
16.2 Repair welding shall be performed using procedures and welders or welding operators that have been qualified in accordance
with the ASME Boiler and Pressure Vessel Code, Section IX.
17. Retests
17.1 If the results of the qualification tests of any lot do not conform to the requirements specified in the applicable product
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specification, retests are permitted on additional lengths of pipe of double the original number from the same lot, each of which
shall conform to the requirements specified. Only one retest of any lot is permitted. Nonconformance of the retest is cause for the
rejection of the lot.
17.2 Any individual length of pipe that meets the test requirements is acceptable. It is permitted to retest individual lengths that
do not conform to the test requirements, provided that the reason for nonconformance is established and the nonconforming portion
is removed.
18. Retreatment
18.1 If individual lengths of pipe selected to represent any lot fail to conform to the test requirements, the lot represented may
be reheat treated and resubmitted for test. The manufacturer may reheat treat the pipe, but not more than twice, except with the
approval of the purchaser.
19. Test Specimens
19.1 Test specimens shall be taken from the ends of finished pipe prior to any forming operations, or being cut to length.
19.2 Specimens cut either longitudinally or transversely shall be acceptable for the tension test.
19.3 If any test specimen shows flaws or defective machining, the specimen may be discarded and another substituted.
20. Flattening Test Requirements
20.1 Seamless and Centrifugally Cast Pipe—A section of pipe not less than 2 ⁄2 in. [60 mm] in length shall be flattened cold
between parallel plates in two steps. During the first step, which is a test for ductility, no cracks or breaks on the inside, outside,
or end surfaces, except as allowed by 21.3.420.3.4, shall occur before the distance between the plates is less than the value of H
calculated as follows:
H 5 1 1 e t⁄ e 1 t ⁄ D (1)
~ ! ~ !
where:
H = distance between flattening plates, in. [mm],
t = specified wall thickness, in. [mm],
D = specified outside diameter, outside diameter corresponding to specified ANSI pipe size, or outside diameter calculated by
adding 2t (as defined above) to the specified inside diameter in. [mm], and
e = deformation per unit length (constant for a given grade of steel, 0.07 for medium carbon steel (maximum specified carbon
0.19 % or greater), 0.08 for ferritic alloy steel, 0.09 for austenitic steel, 0.09 for duplex (ferritic/austenitic) stainless steel,
and 0.09 for low-carbon steel (maximum specified carbon 0.18 % or less)).
During the second step, which is a test for soundness, the flattening shall be continued until the specimen breaks or the opposite
walls of the specimen meet.
20.2 Welded Pipe—A section of welded pipe not less than 4 in. [100 mm] in length shall be flattened cold between parallel plates
in two steps. The weld shall be placed at 90° from the direction of the applied force (at the point of maximum bending). During
the first step, which is a test for ductility, no cracks or breaks on the inside or outside surfaces, except as provided for in
21.3.420.3.4, shall occur before the distance between the plates is less than the value of H calculated by Eq 21. During the second
step, which is a test for soundness, the flattening shall be continued until the specimen breaks or the opposite walls of the specimen
meet.
20.3 Seamless, Centrifugally Cast, and Welded Pipe:
20.3.1 Evidence of laminated or defective material or weld that is revealed at any time during the entire flattening test shall be
cause for rejection.
20.3.2 Surface imperfections not evident in the test specimen before flattening, but revealed during the first step of the flattening
test, shall be judged in accordance with the finish requirements.
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20.3.3 Superficial ruptures resulting from surface imperfections shall not be a cause for rejection.
20.3.4 When low D-to-t ratio tubular products are tested, because the strain imposed due to geometry is unreasonably high on the
inside surface at the six and twelve o’clock locations, cracks at these locations shall not be cause for rejection if the D-to-t ratio
is less than 10.
21. Nondestructive Test Requirements
21.1 If required by the applicable product specification or the purchase order, the pipe shall be tested by the hydrostatic test (see
22.221.2) or by the nondestructive electric test (see 22.321.3).
21.2 Hydrostatic Test:
21.2.1 Except as allowed by 22.2.221.2.2 and 22.2.321.2.3, each length of pipe shall be tested by the manufacturer to a hydrostatic
pressure that will produce in the pipe wall a stress not less than 60 % of the specified minimum yield strength for ferritic alloy
steel and stainless steel pipe, or 50 % of the specified minimum yield strength for austenitic alloy and stainless steel pipe and for
ferritic/austenitic stainless steel pipe. The test pressure or stress shall be determined using the following equation:
P 5 2St⁄DorS 5 PD⁄2t (2)
where:
P = hydrostatic test pressure in psi [MPa],
S = pipe wall stress in psi or [MPa],
t = specified wall thickness, nominal wall thickness according to specified ANSI schedule number, or 1.143 times the specified
minimum wall thickness, in. [mm], and
D = specified outside diameter, outside diameter corresponding to specified ANSI pipe size, or outside diameter calculated by
adding 2t (as defined above) to the specified inside diameter, in. [mm].
21.2.1.1 The hydrostatic test pressure determined by Eq 32 shall be rounded to the nearest 50 psi [0.5 MPa] for pressures below
1000 psi [7 MPa], and to the nearest 100 psi [1 MPa] for pressures 1000 psi [7 MPa] and above. The hydrostatic test may be
performed prior to cutting to final length, or prior to upsetting, swaging, expanding, bending, or other forming operations.
21.2.2 Regardless of pipe-wall stress-level determined by Eq 32, the minimum hydrostatic test pressure required to satisfy these
requirements need not exceed 2500 psi [17.0 MPa] for outside diameters (see D in 22.221.2) of 3.5 in. [88.9 mm] or less, or 2800
psi [19.0 MPa] for outside diameters over 3.5 in. [88.9 mm]. This does not prohibit testing at higher pressures at the option of the
manufacturer or as allowed by 22.2.321.2.3.
21.2.3 With concurrence of the manufacturer, a minimum hydrostatic test pressure in excess of the requirements of 22.121.1 or
22.221.2, or both, may be stated in the purchase order.
21.2.4 The test pressure shall be held for a minimum of 5 s. For welded pipe, the test pressure shall be held for a time sufficient
to permit the entire length of the welded seam to be inspected.
21.2.5 The hydros
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