ASTM F912-11(2017)

Standard Specification for Alloy Steel Socket Set Screws

ABSTRACT
This specification covers the requirements and corresponding test methods for quenched and tempered alloy steel socket set screws (SSS) having sizes of M1.6 through M24, hardnesses of 45 to 53 HRC, and belonging to ISO 898/5 property class 45H. These set screws are intended for compression applications only and are not customarily subjected to embrittlement tests. The screws shall be fabricated to a fine grain practice in standard surface finishes, and optional protective coating as specified in the purchase order. Sampled specimens shall undergo heat and product analysis for measurements of the chemical content for carbon, phosphorus, and sulfur. Appropriate tests shall also be performed to analyze the conformance of the screws to mechanical and other property requirements such as torque and torsional strength, microhardness, decarburization, and surface discontinuities.
SCOPE
1.1 This specification covers the requirements for quenched and tempered alloy steel socket-set screws (SSS) in nominal diameters 0.060 through 2 in. having hardnesses 45 to 53 HRC.  
1.2 These set screws are intended for compression applications only and are not customarily subjected to embrittlement tests. For tensile applications, consult with the manufacturer for proper alloy and hardness.  
1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.
Note 1: A complete metric companion to Specification F912 has been developed—F912M; therefore, no metric equivalents are shown in this Specification.  
1.4 The hazard statement pertains only to the test method section, Section 11 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 and health 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-May-2017
• ICS: 21.060.10 - Bolts, screws, studs
• Technical Committee: F16 - Fasteners
• Drafting Committee: F16.02 - Steel Bolts, Studs and Nuts

Relations

• Replaces: ASTM F912-11 - Standard Specification for Alloy Steel Socket Set Screws
• Effective Date: 01-Jun-2017
• Refers: ASTM F1470-24 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 01-Jan-2024
• Refers: ASTM F788-13(2018) - Standard Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series
• Effective Date: 01-Sep-2018
• Refers: ASTM F1470-18 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 01-Feb-2018
• Refers: ASTM F606/F606M-16 - Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
• Effective Date: 01-Sep-2016
• Refers: ASTM F606/F606M-14a - Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets
• Effective Date: 01-Nov-2014
• Refers: ASTM F2328-14 - Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws, Studs, and Nuts
• Effective Date: 01-Aug-2014
• Refers: ASTM A751-14 - Standard Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
• Effective Date: 01-Mar-2014
• Refers: ASTM F788-13 - Standard Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series
• Effective Date: 01-Apr-2013
• Refers: ASTM E112-12 - Standard Test Methods for Determining Average Grain Size
• Effective Date: 15-Nov-2012
• Refers: ASTM F1470-12 - Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection
• Effective Date: 15-Nov-2012
• Refers: ASTM F2328-05(2011) - Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws and Studs
• Effective Date: 01-May-2011
• Refers: ASTM E112-10 - Standard Test Methods for Determining Average Grain Size
• Effective Date: 01-Nov-2010
• Refers: ASTM E384-10e1 - Standard Test Method for Knoop and Vickers Hardness of Materials
• Effective Date: 01-Feb-2010
• Refers: ASTM E384-10 - Standard Test Method for Microindentation Hardness of Materials
• Effective Date: 01-Feb-2010

Overview

ASTM F912-11(2017) sets the standard specification for quenched and tempered alloy steel socket set screws (SSS) with nominal diameters ranging from 0.060 to 2 inches, and hardness values between 45 and 53 HRC. Developed by ASTM International, this standard addresses alloy steel set screws intended specifically for compression applications. It details manufacturing, mechanical, chemical, and testing requirements to ensure the reliability and safety of these fasteners, which are widely used across a variety of industrial sectors. Compliance with ASTM F912 supports consistent product quality, interchangeability, and safety.

Key Topics

• Material Requirements: Alloy steel, containing elements such as chromium, nickel, molybdenum, or vanadium, must meet strict chemical composition criteria for durability and strength.
• Manufacturing Process: Screws are to be fabricated using fine grain practices, and may be forged, formed, extruded, machined, or ground. Heat treatment involves oil quenching and tempering to achieve the specified hardness.
• Mechanical Properties: The standard defines torque and torsional strength requirements, along with microhardness and decarburization limits to ensure mechanical integrity under compression loads.
• Surface Finishes and Coatings: Unless otherwise specified, socket set screws are supplied as uncoated (bright), thermal black oxide, or chemical black oxide. Additional coatings may be applied if noted in the purchase order, with precautions taken to minimize embrittlement.
• Dimensional Conformance: Products must adhere to ASME B18.3 for dimensions and tolerances, ensuring compatibility and interchangeability.
• Inspection and Certification: The standard includes provisions for inspection, certification, and packaging, as well as the requirements for test reports verifying compliance.

Applications

Alloy steel socket set screws compliant with ASTM F912 are essential components in:

• Mechanical Assemblies: Used for securing components on shafts, collars, and pulleys in compression settings, without relying on tensile strength.
• Aerospace and Defense: The standard is approved for use by U.S. Department of Defense agencies, reflecting reliability in critical systems.
• Automotive Manufacturing: Ensures performance and safety in assemblies subject to vibration and load without direct tensile demands.
• Industrial Machinery: Applied in gear assemblies and retaining applications where compressive force is predominant.
• Construction and Infrastructure: Provides reliable fastening in structural and mechanical systems that require standardized, robust fasteners.

Compliance with ASTM F912 ensures that the set screws offer consistent performance, making them ideal for safety-critical and high-precision applications.

Related Standards

For further technical detail and additional requirements, ASTM F912 references and is associated with several other key standards:

• ASTM A751: Chemical analysis of steel products
• ASTM E112: Determining average grain size
• ASTM E384: Microindentation hardness
• ASTM F606/F606M: Mechanical properties of threaded fasteners
• ASTM F788: Surface discontinuities of bolts, screws, and studs
• ASTM F1470: Sampling for mechanical properties and performance inspection
• ASTM F2328: Decarburization and carburization testing
• ASME B18.3: Socket cap, shoulder, and set screw dimensions
• ASME B18.24: Part identifying number (PIN) code system

These standards collectively ensure rigorous control over the entire lifecycle of alloy steel socket set screws, from material selection and manufacturing through to performance and quality assurance.

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Keywords: ASTM F912, alloy steel socket set screws, SSS, mechanical fasteners, quenched and tempered, compression applications, industrial fasteners, set screw standard, ASME B18.3, fastener certification.

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: F912 −11 (Reapproved 2017)
Standard Specification for
Alloy Steel Socket Set Screws
ThisstandardisissuedunderthefixeddesignationF912;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* E3 Guide for Preparation of Metallographic Specimens
E112 Test Methods for Determining Average Grain Size
1.1 This specification covers the requirements for quenched
E384 Test Method for Microindentation Hardness of Mate-
and tempered alloy steel socket-set screws (SSS) in nominal
rials
diameters0.060through2in.havinghardnesses45to53HRC.
F606/F606M Test Methods for Determining the Mechanical
1.2 These set screws are intended for compression applica-
Properties of Externally and Internally Threaded
tions only and are not customarily subjected to embrittlement
Fasteners, Washers, Direct Tension Indicators, and Rivets
tests. For tensile applications, consult with the manufacturer
F788 Specification for Surface Discontinuities of Bolts,
for proper alloy and hardness.
Screws, and Studs, Inch and Metric Series
F1470 Practice for Fastener Sampling for Specified Me-
1.3 The values stated in inch-pound units are to be regarded
as standard. No other units of measurement are included in this chanical Properties and Performance Inspection
F2328 Test Method for Determining Decarburization and
standard.
Carburization in Hardened and Tempered Threaded Steel
NOTE 1—Acomplete metric companion to Specification F912 has been
Bolts, Screws, Studs, and Nuts
developed—F912M; therefore, no metric equivalents are shown in this
2.2 ASME Standards:
Specification.
B18.3 Socket Cap, Shoulder and Set Screw, Inch Series
1.4 The hazard statement pertains only to the test method
B18.24 Part Identifying Number (PIN) Code System Stan-
section, Section 11 of this specification.Thisstandarddoesnot
dard for B18 Fastener Products
purport to address all of the safety concerns, if any, associated
with its use. It is the responsibility of the user of this standard
3. Ordering Information
to establish appropriate safety and health practices and
3.1 Orders for material under this specification shall include
determine the applicability of regulatory limitations prior to
the following information:
use.
3.1.1 Quantity (number of screws).
1.5 This international standard was developed in accor-
3.1.2 Dimensions, including nominal thread designation,
dance with internationally recognized principles on standard-
threads per inch, nominal screw length (inches) and point
ization established in the Decision on Principles for the
configuration. A standard part number may be used for this
Development of International Standards, Guides and Recom-
definition.
mendations issued by the World Trade Organization Technical
3.1.3 Name of the screw (SSS).
Barriers to Trade (TBT) Committee.
3.1.4 Coating, if required. See 4.4.
3.1.5 Certification, if required. See 14.1.
2. Referenced Documents
3.1.6 ASTM designation and year of issue.
2.1 ASTM Standards:
3.1.7 Any special or supplemental requirements.
A751 Test Methods, Practices, and Terminology for Chemi-
3.1.8 For establishment of a part identifying system, see
cal Analysis of Steel Products
ASME B18.24.
4. Materials and Manufacture
This specification is under the jurisdiction of ASTM Committee F16 on
Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,
4.1 The screws shall be fabricated from alloy steel made to
Nuts, Rivets and Washers.
fine grain practice. In the event of controversy over grain size,
Current edition approved June 1, 2017. Published June 2017. Originally
approved in 1986. Last previous edition approved in 2011 as F912 – 11. DOI:
10.1520/F0912-11R17. Available from American Society of Mechanical Engineers (ASME), ASME
For referenced ASTM standards, visit the ASTM website, www.astm.org, or International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM www.asme.org.
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.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
F912 − 11 (2017)
referee tests on finished screws conducted in accordance with 6.2 Socket set screws shall have a hardness of 45 to 53
Test Methods E112 shall prevail. HRC. The hardness limits shall apply throughout the screw
from core to surface.
4.2 The screws may be forged, formed, extruded, machined,
or ground to meet the dimensional characteristics and perfor-
7. Other Requirements
mance requirements.
7.1 Decarburization:
4.3 Setscrewsshallbeheattreatedbyquenchinginoilfrom
7.1.1 There shall be no evidence of gross decarburization of
above the transformation temperature and then tempered by
the surfaces of the heat-treated screws when measured in
reheating to meet the hardness range specified in 6.2.
accordance with 11.4.
4.4 Standard Finishes—Unless otherwise specified, the
7.1.2 The depth of partial decarburization shall be limited to
screws shall be furnished with one of the following standard
the values in Test Method F2328 (Class 3 Product) when
surfacesasmanufactured,attheoptionofthemanufacturer;(1)
measured as described therein.
bright uncoated;(2) thermal black oxide; or(3) chemical black
oxide. Hydrogen embrittlement tests shall not be required for
8. Dimensions
screws furnished in these conditions.
8.1 Unless otherwise specified, the product shall conform to
4.5 Protective Coatings:
the requirements of ASME B 18.3.
4.5.1 When a protective finish other than as specified in 4.4
is required, it shall be specified on the purchase order with the
9. Workmanship, Finish, and Appearance
applicable finish specification.
9.1 Surface Discontinuities:
4.5.2 When protective or decorative coatings are applied to
9.1.1 The surface discontinuities for these products shall
the screws, precautions specified by the coating requirements
conform to Specification F788 and the additional limitations
to minimize embrittlement shall be exercised.
specified herein.
9.1.2 Processing defects that connect the socket to the
5. Chemical Composition
periphery of the screw are not permissible. Defects originating
5.1 The chemical composition of the screw material shall
on the periphery and with a traverse indicating a potential to
conform to the heat analysis specified in Table 1.
intersect are not permissible.
5.2 One or more of the following alloying elements:
9.1.3 Quench cracks of any depth, any length, or in any
chromium, nickel, molybdenum, or vanadium shall be present location are not permitted.
in the steel in sufficient quantity to assure the specific strength
properties are met after oil quenching and tempering. The steel
10. Number of Tests
shall meet the AISI definition of alloy steel, that is, maximum
10.1 Practice F1470 shall be used to determine the neces-
and minimum element content requirement or minimum ele-
sary sampling plan and the number of tests that must be
ment limits specified.
performed to demonstrate a
...