ASTM B42-20

Standard Specification for Seamless Copper Pipe, Standard Sizes

ABSTRACT
This specification covers seamless copper pipe in all nominal standard pipe sizes, both regular and extra-strong, suitable for use in plumbing, boiler feed lines, and for similar purposes. The material shall conform to the specified chemical requirements. The pipe shall be produced from one of C10200, C10300, C10800, C12000, and C12200 copper UNS numbers. All pipes shall normally be furnished in the prescribed annealed, light drawn, or hard drawn temper. The pipe shall be made from copper that is free of cuprous oxide, as determined by microscopical examination. The pipe shall be subjected to expansion or flattening, Eddy-current, and hydrostatic tests. Samples for chemical analysis shall be taken in accordance with Practice E255. However, the manufacturer shall have the option of determining conformance by analyzing samples taken at the time the castings are poured or from the semifinished product, subject to the conditions set in the specification.
SIGNIFICANCE AND USE
15.1 For purposes of determining compliance with the specified limits for requirements of the properties listed in the following table, an observed value or a calculated value shall be rounded as indicated in accordance with the rounding method of Practice E29.    
Property  
Rounded Unit for
Observed or Calculated Value  
Chemical composition  
nearest unit in the last right-hand place of figures of the specified limit  
Tensile strength
Yield strength  
nearest ksi (nearest 5 MPa)
SCOPE
1.1 This specification2 establishes the requirements for seamless copper pipe in all nominal or standard pipe sizes, both regular and extra-strong, suitable for use in plumbing, boiler feed lines, and for similar purposes.3  
1.2 Units—The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematical conversions to SI units, which are provided for information only and are not considered standard.  
1.3 The following safety hazard caveat pertains only to the test methods described in this specification.  
1.3.1 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.  
1.4 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-Mar-2020
• ICS: 77.150.30 - Copper products
• Technical Committee: B05 - Copper and Copper Alloys
• Drafting Committee: B05.04 - Pipe and Tube

Relations

• Replaces: ASTM B42-15a - Standard Specification for Seamless Copper Pipe, Standard Sizes
• Effective Date: 01-Apr-2020
• Refers: ASTM E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM B846-19a - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Aug-2019
• Refers: ASTM B577-19 - Standard Test Methods for Detection of Cuprous Oxide (Hydrogen Embrittlement Susceptibility) in Copper
• Effective Date: 01-Apr-2019
• Refers: ASTM B846-19 - Standard Terminology for Copper and Copper Alloys
• Effective Date: 01-Jan-2019
• Refers: ASTM B601-18a - Standard Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
• Effective Date: 01-Oct-2018
• Refers: ASTM E243-18 - Standard Practice for Electromagnetic (Eddy Current) Examination of Copper and Copper-Alloy Tubes
• Effective Date: 01-Jun-2018
• Refers: ASTM B601-18 - Standard Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
• Effective Date: 01-Mar-2018
• Refers: ASTM B601-16 - Standard Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
• Effective Date: 01-Oct-2016
• Refers: ASTM E8/E8M-16 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 15-Jul-2016
• Refers: ASTM B577-16 - Standard Test Methods for Detection of Cuprous Oxide (Hydrogen Embrittlement Susceptibility) in Copper
• Effective Date: 01-Apr-2016
• Refers: ASTM B170-99(2015) - Standard Specification for Oxygen-Free Electrolytic Copper—Refinery Shapes
• Effective Date: 15-Oct-2015
• Refers: ASTM E8/E8M-15 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Feb-2015
• Refers: ASTM E243-13 - Standard Practice for Electromagnetic (Eddy Current) Examination of Copper and Copper-Alloy Tubes
• Effective Date: 01-Dec-2013
• Refers: ASTM E8/E8M-13 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jun-2013

Overview

ASTM B42-20 is the internationally recognized standard specification for seamless copper pipe produced in standard sizes. Developed by ASTM International, this specification covers both regular and extra-strong pipes that meet the chemical and mechanical requirements necessary for demanding applications, such as plumbing systems, boiler feed lines, and related uses. Copper pipes conforming to ASTM B42-20 are produced from high-purity copper grades, ensuring durability, corrosion resistance, and consistent performance.

This standard establishes requirements for the composition, mechanical properties, permissible dimensional variations, and testing methods for seamless copper pipes. The primary copper materials covered are designated by UNS numbers C10200, C10300, C10800, C12000, and C12200. Pipes can be supplied in annealed, light drawn, or hard drawn tempers, according to the intended use and customer specifications.

Key Topics

• Material Requirements: Pipes must be made from copper that meets minimum composition and quality standards, particularly with regard to copper content (including silver) and phosphorus limits.
• Standard Sizes: Coverage includes a full range of standard nominal pipe sizes, in both regular and extra-strong wall thicknesses.
• Manufacturing and Temper: Pipes are provided in specific tempers (annealed, light drawn, or hard drawn) as per Classification B601 to suit different installation and service conditions.
• Testing and Inspection:
  • Mechanical tests: Tensile strength and yield strength requirements must be met, following recognized ASTM procedures.
  • Performance tests: Includes expansion or flattening tests, as well as nondestructive eddy-current testing and hydrostatic pressure testing for leak resistance.
  • Microscopical examination: Ensures copper is free from cuprous oxide, to avoid embrittlement.
• Dimensional Tolerances: Strict controls on diameter, wall thickness, roundness, straightness, and squareness of ends ensure consistency and fit with piping systems.
• Packaging and Marking: Detailed provisions for the separation, protection, and marking of copper pipes during shipment, ensuring easy identification and traceability.

Applications

ASTM B42-20 seamless copper pipe is widely used in industries where high-quality, durable piping is critical:

• Plumbing Systems: Ideal for water distribution and service lines in residential, commercial, and institutional buildings, thanks to copper's corrosion resistance and reliability.
• Boiler Feed Lines: Suitable for high-pressure environments, ensuring safe and leak-free operation.
• Heating and Cooling Systems: Used in HVAC plumbing due to excellent thermal conductivity and resistance to mechanical stresses.
• Industrial Piping: Trusted in chemical and manufacturing plants for transporting non-reactive or critical fluids.
• Government and Military Installations: Meets additional supplementary requirements for traceability, identification, and documentation as specified for use in US federal and defense applications.

Related Standards

• ASTM B153 - Test Method for Expansion (Pin Test) of Copper and Copper-Alloy Pipe and Tubing
• ASTM B577 - Detection of Cuprous Oxide in Copper
• ASTM B601 - Classification for Temper Designations for Copper and Copper Alloys
• ASTM B968/B968M - Flattening Test of Copper and Copper-Alloy Pipe and Tube
• ASTM E243 - Practice for Electromagnetic (Eddy Current) Examination of Copper and Copper-Alloy Tubes
• ASME Boiler and Pressure Vessel Code - For pressure piping applications referencing copper pipe
• Federal and Military Packaging Standards - Packaging, preservation, and marking for government usage

For those involved in piping system design, procurement, or installation, compliance with ASTM B42-20 ensures the copper pipe used meets globally recognized quality, safety, and performance requirements. This standard is essential for contractors, engineers, manufacturers, and government agencies emphasizing reliability and traceability in copper piping solutions.

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:B42 −20
Standard Specification for
Seamless Copper Pipe, Standard Sizes
ThisstandardisissuedunderthefixeddesignationB42;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* B577TestMethodsforDetectionofCuprousOxide(Hydro-
gen Embrittlement Susceptibility) in Copper
1.1 This specification establishes the requirements for
B601ClassificationforTemperDesignationsforCopperand
seamlesscopperpipeinallnominalorstandardpipesizes,both
Copper Alloys—Wrought and Cast
regular and extra-strong, suitable for use in plumbing, boiler
3 B846Terminology for Copper and Copper Alloys
feed lines, and for similar purposes.
B968/B968MTest Method for Flattening of Copper and
1.2 Units—The values stated in inch-pound units are to be
Copper-Alloy Pipe and Tube
regarded as the standard. The values given in parentheses are
E8/E8MTest Methods for Tension Testing of Metallic Ma-
mathematical conversions to SI units, which are provided for
terials
information only and are not considered standard.
E29Practice for Using Significant Digits in Test Data to
1.3 The following safety hazard caveat pertains only to the Determine Conformance with Specifications
E53Test Method for Determination of Copper in Unalloyed
test methods described in this specification.
1.3.1 This standard does not purport to address all of the Copper by Gravimetry
E62Test Methods for Chemical Analysis of Copper and
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- CopperAlloys(PhotometricMethods)(Withdrawn2010)
E243PracticeforElectromagnetic(EddyCurrent)Examina-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. tion of Copper and Copper-Alloy Tubes
E255Practice for Sampling Copper and Copper Alloys for
1.4 This international standard was developed in accor-
the Determination of Chemical Composition
dance with internationally recognized principles on standard-
E478Test Methods for ChemicalAnalysis of CopperAlloys
ization established in the Decision on Principles for the
E527Practice for Numbering Metals and Alloys in the
Development of International Standards, Guides and Recom-
Unified Numbering System (UNS)
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 2.2 ASME Code:
ASMEBoiler and Pressure Vessel Code
2. Referenced Documents
3. Terminology
2.1 ASTM Standards:
B153Test Method for Expansion (Pin Test) of Copper and
3.1 Definitions:
Copper-Alloy Pipe and Tubing
3.1.1 For definitions of terms related to copper and copper
B170Specification for Oxygen-Free Electrolytic Copper—
alloys, refer to Terminology B846.
Refinery Shapes
4. Ordering Information
ThisspecificationisunderthejurisdictionofASTMCommitteeB05onCopper
4.1 Include the following specified choices when placing
and CopperAlloys and is the direct responsibility of Subcommittee B05.04 on Pipe
orders for product under this specification as applicable:
and Tube.
Current edition approved April 1, 2020. Published April 2020. Originally
4.1.1 ASTM designation and year of issue;
approved in 1922. Last previous edition approved in 2015 as B42–15a. DOI:
4.1.2 CopperUNSNo.designation,ifrequired,(seeChemi-
10.1520/B0042–20.
cal Composition section);
For ASME Boiler and Pressure Vessel Code applications, see related Specifi-
4.1.3 Temper (see Temper section and Table 2);
cation SB-42 in Section II of that Code.
The UNS system for copper and copper alloys (see Practice E527) is a simple
expansion of the former standard designation system accomplished by the addition
of a prefix “C” and a suffix “00.” The suffix can be used to accommodate
composition variations of the base alloy. The last approved version of this historical standard is referenced on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Available from American Society of Mechanical Engineers (ASME), ASME
Standards volume information, refer to the standard’s Document Summary page on International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
the ASTM website. www.asme.org.
*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
B42−20
4.1.4 Pipe size, regular or extra-strong (see Dimensions 5.3 When the copper UNS No. designation is specified, the
section and Table 3); material shall conform to the chemical requirements specified
4.1.5 Length (see 10.3) if different than standard; and in Table 1.
4.1.6 Quantity—total weight, or total length or number of
5.4 These composition limits do not preclude the presence
pieces of each size.
of other elements. By agreement between manufacturer or
4.2 The following options are available, but may not be supplier and purchaser, limits may be established and analysis
included unless specified at the time of placing of the order required for unnamed elements.
when required:
6. Temper
4.2.1 If product is ordered for ASME Boiler and Pressure
Vessel Code Application (See Certification Section); 6.1 The standard tempers as prescribed in Classification
4.2.2 If product is required for bending (see 6.2) and the B601, for products described in this specification are:
temper to be furnished; 6.1.1 Annealed O61,
4.2.3 Certification, if required (see Certification section); 6.1.2 Light Drawn H55, and
4.2.4 Test report, if required (see Test Report section); 6.1.3 Hard Drawn H80.
4.2.5 Hydrostatic test, if required (see Nondestructive Test-
6.2 When pipe is required for bending, it shall be so
ing section);
specified in the purchase order, and the pipe shall be furnished
4.2.5.1 If hydrostatic test pressure above 1000 psi is re-
in the temper agreed upon between the manufacturer or
quired;
supplier and the purchaser.
4.2.6 Pneumatic test, if required (see Nondestructive Test-
ing section); 7. Mechanical Property Requirements
4.2.7 If product is purchased for agencies of the U.S.
7.1 Tensile Strength Requirements:
Government (see the Other Requirements section of this
7.1.1 Product furnished under this specification shall con-
specification); and
form to the tensile requirements prescribed in Table 2, when
4.2.8 If specification number is required to be shown on
tested in accordance with Test Methods E8/E8M.
each shipping unit (see Packaging and Package Marking
section). 8. Performance Requirements
8.1 Expansion Test:
5. Chemical Composition
8.1.1 Pipe ordered in the annealed (O61) temper, selected
5.1 The material shall conform to the following chemical
for test, shall withstand an expansion of 25% of the outside
requirements:
diameter when expanded in accordance with Test Method
B153. The expanded pipe shall show no cracking or rupture
Copper (incl silver), min, % 99.9
Phosphorus, max, % 0.04
visible to the unaided eye. Pipe ordered in the drawn tempers
H55 or H80 are not subject to this test.
5.1.1 Results of analysis on a product (check) sample shall
conform to the composition requirements within the permitted
NOTE 1—The term “unaided eye,” as used herein, permits the use of
analytical variance specified in Table 1.
corrective spectacles necessary to obtain normal vision.
5.2 The pipe shall be produced from one of the following
8.2 Flattening Test:
coppers, and unless otherwise specified, any one of them is
8.2.1 As an alternative to the expansion test for pipe over
permitted to be furnished:
4in. (102 mm) in diameter in the annealed temper, a flattening
Previously Used test in accordance with Test Method B968/B968M shall be
Copper UNS No. Type of Copper
Designation
performed.
C10200 OF Oxygen-free without residual
8.3 Microscopical Examination:
deoxidants
8.3.1 The pipe shall be made from copper that is free of
C10300 Oxygen-free, extra-low phosphorus
cuprous oxide as determined by microscopical examination in
C10800 Oxygen-free, low phosphorus
C12000 DLP Phosphorized, low residual
accordance with Method A of Test Methods B577 at a 75×
phosphorus
magnification.
C12200 DHP Phosphorized, high residual
phosphorus
TABLE 2 Tensile Requirements
Tensile
C
Temper Designation Pipe Size
Yield Strength,
Strength,
Nominal or min.
min, A B
TABLE 1 Chemical Requirements
ksi (MPa)
Code Name Standard, in.
A B
ksi (MPa)
Copper UNS No. Copper (incl Silver), min, % Phosphorus, % D
O61 annealed all 30 (205) 9 (60)
A
C10200 99.95 . H80 hard drawn ⁄8 –2, incl 45 (310) 40 (275)
B
C10300 99.95 0.001 to 0.005 H80 hard drawn over 2 38 (260) 32 (220)
B
C10800 99.95 0.005 to 0.012 H55 light drawn 2–12, incl 36 (250) 30 (205)
C12000 99.90 0.004 to 0.012
A
ksi = 1000 psi.
C12200 99.9 0.015 to 0.040
B
See Appendix X1.
A C
Oxygen in C10200 shall be 10 ppm max. At 0.5 % extension under load.
B D
Copper + silver + phosphorus. Light-straightening operation is permitted.
B42−20
8.3.2 When Copper UNS No. C12200 is supplied, micro- 9.5 Purchases for U.S. Government—If the product is pur-
scopical examination for cuprous oxide is not required. chasedforagenciesoftheU.S.Government,whenspecifiedin
the contract or purchase order, the product furnished shall
9. Other Requirements
conform to the conditions specified in the Supplementary
Requirements of this specification.
9.1 Nondestructive Testing:
9.1.1 The material shall be tested in the final size but is
10. Dimensions and Permissible Variations
permitted to be tested before the final anneal or heat treatment,
10.1 For the purpose of determining conformance with the
when these thermal treatments are required, unless otherwise
dimensional requirements prescribed in this specification, any
agreed upon by the manufacturer or supplier and purchaser.
measured value outside the limiting values for any dimensions
9.2 Eddy-Current Test—Each piece of material from ⁄8 in.
shall be sufficient cause for rejection.
uptoandincluding2 ⁄2in.nominaloutsidediameter,orwithin
10.2 Standard Dimensions, Wall Thickness, and Diameter
the capabilities of the eddy-current tester, shall be subjected to
Tolerances—The standard dimensions, wall thickness, and
an eddy-current test. Testing shall follow the procedures of
diameter tolerances shall be in accordance with Table 3.
Practice E243, except for determination of “end effect.” The
material shall be passed through an eddy-current testing unit 10.3 Length and Length Tolerances—Thestandardlengthof
adjusted to provide information on the suitability of the copper pipe is 12 ft (3.66 m) with a tolerance of 6 ⁄2 in.
material for the intended application. (13mm).
9.2.1 Notch-depthstandardsroundedtothenearest0.001in.
10.4 Roundness:
(0.025 mm) shall be 10% of the nominal wall thickness. The
10.4.1 ForpipeofH(drawn)tempersinstraightlengths,the
notch depth tolerance shall be 60.0005 in. (0.013 mm).
roundness tolerances shall be as follows:
Alternatively, when a manufacturer uses speed-insensitive
Roundness Tolerances as
t/d (ratio of
equipment that allows the selection of a maximum imbalance
Percent of Outside Diameter
Wall Thickness to
signal, a maximum imbalance signal of 0.3% is permitted to (Expressed to the Nearest
Outside Diameter)
0.001 in. (0.025 mm))
be used.
9.2.2 Material that does not actuate the signaling device of
0.01 to 0.03, incl 1.5
the eddy-current test shall be considered as conforming to the Over 0.03 to 0.05, incl 1.0
Over 0.05 to 0.10, incl 0.8
requirements of this test. Material with discontinuities indi-
Over 0.10 0.7
cated by the testing unit is permitted to be re-examined or
10.4.2 Compliance with the roundness tolerance shall be
retested, at the option of the manufacturer, to determine
determined by taking measurements on the outside diameter
whetherthediscontinuityiscauseforrejection.Signalsthatare
only, irrespective of the manner in which the pipe dimensions
found to have been caused by minor mechanical damage, soil,
are specified.
or moisture shall not be cause for rejection of the material
10.4.3 The deviation from roundness is measured as the
provided the dimensions of the material are still within
differencebetweenmajorandminordiametersasdeterminedat
prescribed limits and the material is suitable for its intended
any one cross section of the tube.
application.
10.5 Squareness of Cut—The departure from squareness of
9.3 Hydrostatic Test—When specified, the material shall
the end of any pipe shall not exceed the following:
stand,withoutshowingevidenceofleakage,aninternalhydro-
Outside Diameter,
static pressure sufficient to subject the material to a fiber stress
Tolerance
in. (mm)
of 6000 psi (41 MPa), determined by the following equation
Up to ⁄8 (15.9), incl 0.010 in. (0.25 mm)
for thin hollow cylinders under tension. The material need not
Over ⁄8 (15.9) 0.016 in./in. (0.016 mm/mm) of diameter
be tested at a hydrostatic pressure of over 1000 psi (6.9 MPa)
10.6 Straightness Tolerance—For pipe of H (drawn) tem-
unless so specified.
pers of nominal pipe sizes from ⁄4 to 12 in. inclusive, the
P 52St/ D 20.8t (1) maximum curvature (depth of arc) shall not exceed ⁄2 in.
~ !
(13mm) in any 10 ft portion of the total length. For H temper
where:
pipe of other sizes, and for the O61 (annealed) temper, no
P = hydrostatic pressure, psi (or MPa);
numerical values are established; however, the straightness of
t = wall thickness of the material, in. (or mm);
the pipe shall be suitable for the intended application.
D = outside diameter of the material in. (or mm); and
S = allowable stress of the material, psi (or MPa).
11. Workmanship, Finish, and Appearance
9.4 Pneumatic Test—When specified, the material shall be 11.1 Theproductshallbefreeofdefects,butblemishesofa
subjected to an internal air pressure of 60 psi (415 kPa)
nature that do not interfere with the intended application are
minimumfor5swithoutshowingevidenceofleakage.Thetest acceptable. It shall be well cleaned and free of dirt.
method used shall permit easy visual detection of any leakage,
12. Sampling
such as by having the material under water or by the pressure-
differentialmethod.Anyevidenceofleakageshallbecausefor 12.1 Sampling—The lot size, portion size, and selection of
rejection.
sample pieces shall be as follows:
B42−20
TABLE 3 Standard Dimensions, Weights, and Tolerances
NOTE 1—All tolerances plus and minus except as otherwise indicated.
Nominal or
Average Outside
Outside Wall
B
Standard Theoretical Weight,
Diameter Tolerance,
Diameter, Thickness,
A
in. (mm)
Pipe Size, lb/ft (kg/m)
Tolerance, in.
in. (mm) in. (mm)
(mm) All Minus
in.
Regular
⁄8 0.405 (10.3) 0.004 (0.10) 0.062 (1.57) 0.004 (0.10) 0.259 (0.385)
⁄4 0.540 (13.7) 0.004 (0.10) 0.082 (2.08) 0.005 (0.13) 0.457 (0.680)
⁄8 0.675 (17.1) 0.005 (0.13) 0.090 (2.29) 0.005 (0.13) 0.641 (0.954)
⁄2 0.840 (21.3) 0.005 (0.13) 0.107 (2.72) 0.006 (0.15) 0.955 (1.42)
⁄4 1.050 (26.7) 0.006 (0.15) 0.114 (2.90) 0.006 (0.15) 1.30 (1.93)
1 1.315 (33.4) 0.006 (0.15) 0.126 (3.20) 0.007 (0.18) 1.82 (2.71)
1 ⁄4 1.660 (42.2) 0.006 (0.15) 0.146 (3.71) 0.008 (0.20) 2.69 (4.00)
1 ⁄2 1.900 (48.3) 0.006 (0.15) 0.150 (3.81) 0.008 (0.20) 3.20 (4.76)
2 2.375 (60.3) 0.008 (0.20) 0.156 (3.96) 0.009 (0.23) 4.22 (6.28)
2 ⁄2 2.875 (73.0) 0.008 (0.20) 0.187 (4.75) 0.010 (0.25) 6.12 (9.11)
3 3.500 (88.9) 0.010 (0.25) 0.219 (5.56) 0.012 (0.30) 8.76 (13.0)
3 ⁄2 4.000 (102) 0.010 (0.25) 0.250 (6.35) 0.013 (0.33) 11.4 (17.0)
4 4.500 (114) 0.012 (0.30) 0.250 (6.35) 0.014 (0.36) 12.9 (19.2)
5 5.562 (141) 0.014 (0.36) 0.250 (6.35) 0.014 (0.36) 16.2 (24.1)
6 6.625 (168) 0.016 (0.41) 0.250 (6.35) 0.014 (0.36) 19.4 (28.9)
8 8.625 (219) 0.020 (0.51) 0.312 (7.92) 0.022 (0.56) 31.6 (47.0)
10 10.750 (273) 0.022 (0.56) 0.365 (9.27) 0.030 (0.76) 46.2 (68.7)
12 12.750 (324) 0.024 (0.61) 0.375 (9.52) 0.030 (0.76) 56.5 (84.1)
Extra Strong
⁄8 0.405 (10.3) 0.004 (0.10) 0.100 (2.54) 0.006 (0.15) 0.371 (0.552)
⁄4 0.540 (13.7) 0.004 (0.10) 0.123 (3.12) 0.007 (0.18) 0.625 (0.930)
⁄8 0.675 (17.1) 0.005 (0.13) 0.127 (3.23) 0.007 (0.18) 0.847 (1.26)
⁄2 0.840 (21.3) 0.005 (0.13) 0.149 (3.78) 0.008 (0.20) 1.25 (1.86)
⁄4 1.050 (26.7) 0.006 (0.15) 0.157 (3.99) 0.009 (0.23
...

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: B42 − 15a B42 − 20
Standard Specification for
Seamless Copper Pipe, Standard Sizes
This standard is issued under the fixed designation B42; 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 establishes the requirements for seamless copper pipe in all nominal or standard pipe sizes, both regular
and extra-strong, suitable for use in plumbing, boiler feed lines, and for similar purposes.
1.2 Units—The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are
mathematical conversions to SI units, which are provided for information only and are not considered standard.
1.3 The following safety hazard caveat pertains only to the test methods described in this specification.
1.3.1 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 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:
B153 Test Method for Expansion (Pin Test) of Copper and Copper-Alloy Pipe and Tubing
B170 Specification for Oxygen-Free Electrolytic Copper—Refinery Shapes
B577 Test Methods for Detection of Cuprous Oxide (Hydrogen Embrittlement Susceptibility) in Copper
B601 Classification for Temper Designations for Copper and Copper Alloys—Wrought and Cast
B846 Terminology for Copper and Copper Alloys
B968/B968M Test Method for Flattening of Copper and Copper-Alloy Pipe and Tube
E8/E8M Test Methods for Tension Testing of Metallic Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E53 Test Method for Determination of Copper in Unalloyed Copper by Gravimetry
E62 Test Methods for Chemical Analysis of Copper and Copper Alloys (Photometric Methods) (Withdrawn 2010)
E243 Practice for Electromagnetic (Eddy Current) Examination of Copper and Copper-Alloy Tubes
E255 Practice for Sampling Copper and Copper Alloys for the Determination of Chemical Composition
E478 Test Methods for Chemical Analysis of Copper Alloys
E527 Practice for Numbering Metals and Alloys in the Unified Numbering System (UNS)
2.2 ASME Code:
ASME Boiler and Pressure Vessel Code
This specification is under the jurisdiction of ASTM Committee B05 on Copper and Copper Alloys and is the direct responsibility of Subcommittee B05.04 on Pipe and
Tube.
Current edition approved July 1, 2015April 1, 2020. Published July 2015April 2020. Originally approved in 1922. Last previous edition approved in 2015 as
B42 – 15.B42–15a. DOI: 10.1520/B0042-15A.10.1520/B0042–20.
For ASME Boiler and Pressure Vessel Code applications, see related Specification SB-42 in Section II of that Code.
The UNS system for copper and copper alloys (see Practice E527) is a simple expansion of the former standard designation system accomplished by the addition of a
prefix “C” and a suffix “00.” The suffix can be used to accommodate composition variations of the base alloy.
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’sstandard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
*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
B42 − 20
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms related to copper and copper alloys, refer to Terminology B846.
4. Ordering Information
4.1 Include the following specified choices when placing orders for product under this specification as applicable:
4.1.1 ASTM designation and year of issue,issue;
4.1.2 Copper UNS No. designation, if required, (see Chemical Composition section),section);
4.1.3 Temper (see Temper section and Table 2),2);
4.1.4 Pipe size, regular or extra-strong,extra-strong (see Dimensions section and Table 3),3);
4.1.5 Length (see 10.3) if different than standard,standard; and
4.1.6 Total length of each size,Quantity—total weight, or total length or number of pieces of each size.
4.2 The following options are available, but may not be included unless specified at the time of placing of the order when
required:
4.2.1 If product is ordered for ASME Boiler and Pressure Vessel Code Application (See Certification Section).Section);
4.2.2 If product is required for bending (see 6.2) and the temper to be furnished,furnished;
4.2.3 Certification, if required (see Certification section),section);
4.2.4 Test report, if required (see Test Report section),section);
4.2.5 Hydrostatic test, if required (see Nondestructive Testing section),section);
4.2.5.1 If hydrostatic test pressure above 1000 psi is required,required;
4.2.6 Pneumatic test, if required (see Nondestructive Testing section).section);
4.2.7 If product is purchased for agencies of the U.S. Government (see the Other Requirements section of this specification,
specification); and
4.2.8 If specification number is required to be shown on each shipping unit (see Packaging and Package Marking
section)section).
5. Chemical Composition
5.1 The material shall conform to the following chemical requirements:
Copper (incl silver), min, % 99.9
Phosphorus, max, % 0.04
5.1.1 Results of analysis on a product (check) sample shall conform to the composition requirements within the permitted
analytical variance specified in Table 1.
5.2 The pipe shall be produced from one of the following coppers, and unless otherwise specified, anyone any one of them is
permitted to be furnished:
Previously Used
Copper UNS No. Type of Copper
Designation
C10200 OF Oxygen-free without residual
deoxidants
C10300 Oxygen-free, extra-low phosphorus
C10800 Oxygen-free, low phosphorus
C12000 DLP Phosphorized, low residual
phosphorus
C12200 DHP Phosphorized, high residual
phosphorus
5.3 When the copper UNS No. designation is specified, the material shall conform to the chemical requirements specified in
Table 1.
5.4 These composition limits do not preclude the presence of other elements. By agreement between manufacturer or supplier
and purchaser, limits may be established and analysis required for unnamed elements.
TABLE 1 Chemical Requirements
Copper UNS No. Copper (incl Silver), min, % Phosphorus, %
A
C10200 99.95 .
B
C10300 99.95 0.001 to 0.005
B
C10800 99.95 0.005 to 0.012
C12000 99.90 0.004 to 0.012
C12200 99.9 0.015 to 0.040
A
Oxygen in C10200 shall be 10 ppm max.
B
Copper + silver + phosphorus.
B42 − 20
6. Temper
6.1 The standard tempers as prescribed in Classification B601, for products described in this specification are:
6.1.1 Annealed O61,
6.1.2 Light Drawn H55H55, and
6.1.3 Hard Drawn H80H80.
6.2 When pipe is required for bending, it shall be so specified in the purchase order, and the pipe shall be furnished in the temper
agreed upon between the manufacturer or supplier and the purchaser.
7. Mechanical Property Requirements
7.1 Tensile Strength Requirements:
7.1.1 Product furnished under this specification shall conform to the tensile requirements prescribed in Table 2, when tested
in accordance with Test Methods E8/E8M.
8. Performance Requirements
8.1 Expansion Test:
8.1.1 Pipe ordered in the annealed (O61) temper, selected for test, shall withstand an expansion of 25 % of the outside diameter
when expanded in accordance with Test Method B153. The expanded pipe shall show no cracking or rupture visible to the unaided
eye. Pipe ordered in the drawn tempers H55 or H80 are not subject to this test.
NOTE 1—The term “unaided eye,” as used herein, permits the use of corrective spectacles necessary to obtain normal vision.
8.2 Flattening Test:
8.2.1 As an alternative to the expansion test for pipe over 4 in. 4 in. (102 mm) in diameter in the annealed temper, a flattening
test in accordance with Test Method B968/B968M shall be performed.
8.3 Microscopical Examination:
8.3.1 The pipe shall be made from copper that is free of cuprous oxide as determined by microscopical examination in
accordance with Method A of Test Methods B577 at a 75× magnification.
8.3.2 When Copper UNS No. C12200 is supplied, microscopical examination for cuprous oxide is not required.
9. Other Requirements
9.1 Nondestructive Testing:
9.1.1 The material shall be tested in the final size but is permitted to be tested before the final anneal or heat treatment, when
these thermal treatments are required, unless otherwise agreed upon by the manufacturer or supplier and purchaser.
1 1
9.2 Eddy-Current Test—Each piece of material from ⁄8-in. in. up to and including 2 ⁄2-in. in. nominal outside diameter, or within
the capabilities of the eddy-current tester, shall be subjected to an eddy-current test. Testing shall follow the procedures of Practice
E243, except for determination of “end effect.” The material shall be passed through an eddy-current testing unit adjusted to
provide information on the suitability of the material for the intended application.
9.2.1 Notch-depth standards rounded to the nearest 0.001 in. (0.025 mm) shall be 10 % of the nominal wall thickness. The notch
depth tolerance shall be 60.0005 in. (0.013 mm). Alternatively, when a manufacturer uses speed-insensitive equipment that allows
the selection of a maximum imbalance signal, a maximum imbalance signal of 0.3 % is permitted to be used.
9.2.2 Material that does not actuate the signaling device of the eddy-current test shall be considered as conforming to the
requirements of this test. Material with discontinuities indicated by the testing unit is permitted to be reexaminedre-examined or
retested, at the option of the manufacturer, to determine whether the discontinuity is cause for rejection. Signals that are found to
have been caused by minor mechanical damage, soil, or moisture shall not be cause for rejection of the material provided the
dimensions of the material are still within prescribed limits and the material is suitable for its intended application.
TABLE 2 Tensile Requirements
Tensile
C
Temper Designation Pipe Size
Yield Strength,
Strength,
Nominal or min.
min, A B
ksi (MPa)
Code Name Standard, in.
A B
ksi (MPa)
D
O61 annealed all 30 (205) 9 (60)
H80 hard drawn ⁄8 –2, incl 45 (310) 40 (275)
H80 hard drawn over 2 38 (260) 32 (220)
H55 light drawn 2–12, incl 36 (250) 30 (205)
A
ksi = 1000 psi.
B
See Appendix X1.
C
At 0.5 % extension under load.
D
Light-straightening operation is permitted.
B42 − 20
9.3 Hydrostatic Test—When specified, the material shall stand, without showing evidence of leakage, an internal hydrostatic
pressure sufficient to subject the material to a fiber stress of 6000 psi (41 MPa), determined by the following equation for thin
hollow cylinders under tension. The material need not be tested at a hydrostatic pressure of over 1000 psi (6.9 MPa) unless so
specified.
P 5 2St/ D 2 0.8t (1)
~ !
where:
P = hydrostatic pressure, psi (or MPa);
t = wall thickness of the material, in. (or mm);
D = outside diameter of the material in. (or mm); and
S = allowable stress of the material, psi (or MPa).
9.4 Pneumatic Test—When specified, the material shall be subjected to an internal air pressure of 60 psi (415 kPa) minimum
for 5 s without showing evidence of leakage. The test method used shall permit easy visual detection of any leakage, such as by
having the material under water or by the pressure-differential method. Any evidence of leakage shall be cause for rejection.
9.5 Purchases for U.S. Government—If the product is purchased for agencies of the U.S. Government, when specified in the
contract or purchase order, the product furnished shall conform to the conditions specified in the Supplementary Requirements of
this specification.
10. Dimensions and Permissible Variations
10.1 For the purpose of determining conformance with the dimensional requirements prescribed in this specification, any
measured value outside the limiting values for any dimensions shall be sufficient cause for rejection.
10.2 Standard Dimensions, Wall Thickness, and Diameter Tolerances—The standard dimensions, wall thickness, and diameter
tolerances shall be in accordance with Table 3.
10.3 Length and Length Tolerances—The standard length of copper pipe is 12 ft (3.66 m) with a tolerance of 6 ⁄2 in. (13
mm).(13 mm).
10.4 Roundness:
10.4.1 For pipe of H (drawn) tempers in straight lengths, the roundness tolerances shall be as follows:
Roundness Tolerances as
t/d (ratio of
Percent of Outside Diameter
Wall Thickness to
(Expressed to the Nearest
Outside Diameter)
0.001 in. (0.025 mm))
0.01 to 0.03, incl 1.5
Over 0.03 to 0.05, incl 1.0
Over 0.05 to 0.10, incl 0.8
Over 0.10 0.7
10.4.2 Compliance with the roundness tolerance shall be determined by taking measurements on the outside diameter only,
irrespective of the manner in which the pipe dimensions are specified.
10.4.3 The deviation from roundness is measured as the difference between major and minor diameters as determined at any
one cross section of the tube.
10.5 Squareness of Cut—The departure from squareness of the end of any pipe shall not exceed the following:
Outside Diameter,
Tolerance
in. (mm)
Up to ⁄8 (15.9), incl 0.010 in. (0.25 mm)
Over ⁄8 (15.9) 0.016 in./in. (0.016 mm/mm) of diameter
10.6 Straightness Tolerance—For pipe of H (drawn) tempers of Nominal Pipe Sizesnominal pipe sizes from ⁄4 to 12 in.
inclusive, the maximum curvature (depth of arc) shall not exceed ⁄2 in. (13 mm) (13 mm) in any 10-ft 10 ft portion of the total
length. For H temper pipe of other sizes, and for the O61 (annealed) temper, no numerical values are established,established;
however, the straightness of the pipe shall be suitable for the intended application.
11. Workmanship, Finish, and Appearance
11.1 The product shall be free of defects, but blemishes of a nature that do not interfere with the intended application are
acceptable. It shall be well cleaned and free of dirt.
12. Sampling
12.1 Sampling—The lot size, portion size, and selection of sample pieces shall be as follows:
B42 − 20
TABLE 3 Standard Dimensions, Weights, and Tolerances
NOTE 1—All tolerances plus and minus except as otherwise indicated.
Nominal or
Average Outside
Outside Wall
B
Standard Theoretical Weight,
Diameter Tolerance,
Diameter, Thickness,
A
Pipe Size, in. (mm) lb/ft (kg/m)
Tolerance, in.
in. (mm) in. (mm)
(mm) All Minus
in.
Regular
⁄8 0.405 (10.3) 0.004 (0.10) 0.062 (1.57) 0.004 (0.10) 0.259 (0.385)
⁄4 0.540 (13.7) 0.004 (0.10) 0.082 (2.08) 0.005 (0.13) 0.457 (0.680)
⁄8 0.675 (17.1) 0.005 (0.13) 0.090 (2.29) 0.005 (0.13) 0.641 (0.954)
⁄2 0.840 (21.3) 0.005 (0.13) 0.107 (2.72) 0.006 (0.15) 0.955 (1.42)
⁄4 1.050 (26.7) 0.006 (0.15) 0.114 (2.90) 0.006 (0.15) 1.30 (1.93)
1 1.315 (33.4) 0.006 (0.15) 0.126 (3.20) 0.007 (0.18) 1.82 (2.71)
1 ⁄4 1.660 (42.2) 0.006 (0.15) 0.146 (3.71) 0.008 (0.20) 2.69 (4.00)
1 ⁄2 1.900 (48.3) 0.006 (0.15) 0.150 (3.81) 0.008 (0.20) 3.20 (4.76)
2 2.375 (60.3) 0.008 (0.20) 0.156 (3.96) 0.009 (0.23) 4.22 (6.28)
2 ⁄2 2.875 (73.0) 0.008 (0.20) 0.187 (4.75) 0.010 (0.25) 6.12 (9.11)
3 3.500 (88.9) 0.010 (0.25) 0.219 (5.56) 0.012 (0.30) 8.76 (13.0)
3 ⁄2 4.000 (102) 0.010 (0.25) 0.250 (6.35) 0.013 (0.33) 11.4 (17.0)
4 4.500 (114) 0.012 (0.30) 0.250 (6.35) 0.014 (0.36) 12.9 (19.2)
5 5.562 (141) 0.014 (0.36) 0.250 (6.35) 0.014 (0.36) 16.2 (24.1)
6 6.625 (168) 0.016 (0.41) 0.250 (6.35) 0.014 (0.36) 19.4 (28.9)
8 8.625 (219) 0.020 (0.51) 0.312 (7.92) 0.022 (0.56) 31.6 (47.0)
10 10.750 (273) 0.022 (0.56) 0.365 (9.27) 0.030 (0.76) 46.2 (68.7)
12 12.750 (324) 0.024 (0.61) 0.375 (9.52) 0.030 (0.76) 56.5 (84.1)
Extra Strong
⁄8 0.405 (10.3) 0.004 (0.10) 0.100 (2.54) 0.006 (0.15) 0.371 (0.552)
⁄4 0.540 (13.7) 0.004 (0.10) 0.123 (3.12) 0.007 (0.18) 0.625 (0.930)
⁄8 0.675 (17.1) 0.005 (0.13) 0.127 (3.23) 0.007 (0.18) 0.847 (1.26)
⁄2 0.840 (21.3) 0.005 (0.13) 0.149 (3.78) 0.008 (0.20) 1.25 (1.86)
⁄4 1.050 (26.7) 0.006 (0.15) 0.157 (3.99) 0.009 (0.23) 1.71 (2.54)
1 1.315 (33.4) 0.006 (0.15) 0.182 (4.62) 0.010 (0.25) 2.51 (3.73)
1 ⁄4 1.660 (42.2) 0.006 (0.15) 0.194 (4.93) 0.010 (0.25) 3.46 (5.15)
1 ⁄2 1.900 (48.3) 0.006 (0.15) 0.203 (5.16) 0.011 (0.28) 4.19 (6.23)
2 2.375 (60.3) 0.008 (0.20) 0.221 (5.61) 0.012 (0.30) 5.80 (8.63)
2 ⁄2 2.875 (73.0) 0.008 (0.20) 0.280 (7.11) 0.015 (0.38) 8.85 (13.2)
3 3.500 (88.9) 0.010 (0.25) 0.304 (7.72) 0.016 (0.41) 11.8 (17.6)
3 ⁄2 4.000 (102) 0.010 (0.25) 0.321 (8.15) 0.017 (0.43) 14.4 (21.4)
4 4.500
...