ASTM F2328-17

Standard Test Method for Determining Decarburization and Carburization in Hardened and Tempered Threaded Steel Bolts, Screws, Studs, and Nuts

SIGNIFICANCE AND USE
4.1 Decarburization and carburization are two surface conditions created, either intentionally or unintentionally, as with a pre-existing condition created during the rod rolling process, the rod/wire annealing process, or while heat treating threaded steel products. Too much of either will adversely affect the safety and performance of the threaded product. Therefore, limits have been established for three different product groups: the harder and greater the tensile strength of the product, the more susceptible to failure the product becomes if these limits are exceeded.  
4.2 When testing to a particular product specification that lists the dimensions and microindentation data to be used, that data shall take precedence over the tables in this test method.  
4.3 There are only two viable methods available to detect these deficiencies, either by the visual method or the microindentation method. Both methods are used for routine inspections when evaluations are conducted at a single location on the product sample.  
4.3.1 Because an evaluation at a specific location may not be representative of the whole part, the referee method employs the microindentation method taken as an average of evaluations conducted on four adjacent threads. This procedure significantly reduces the random test variables when compared to testing on a single thread.  
4.4 Specifying this test method does not specify or imply that testing shall be for either decarburization or carburization alone or for both conditions. When either test method is performed, both conditions will be apparent and shall be reported. For example, if an order is placed to test for decarburization and none is found, but the presence of carburization is detected, it shall be reported on the test report that carburization was found.
SCOPE
1.1 This test method covers procedures for measuring, classifying, and determining the presence of decarburization and carburization in the threaded section of hardened and tempered inch series steel bolts, screws, studs, nuts, and similar parts which have been heated to facilitate fabrication or to modify their mechanical properties. This test method is not intended to address products which are intentionally carburized to achieve specific results.  
1.2 Two routine methods are described for measuring the limits of and determining the presence of decarburization or carburization—the optical method and the microindentation method 1. Either method is appropriate for routine examinations. The microindentation method 2 shall be considered the referee method.  
1.3 For the purpose of these tests, there are four classes of hardened and tempered steel products for which specific measurements must be made with respect to their physical properties.  
1.4 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.  
1.6 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: Historical
• Publication Date: 31-Aug-2017
• ICS: 21.060.01 - Fasteners in general
• ICS: 77.140.20 - Stainless steels
• Technical Committee: F16 - Fasteners
• Drafting Committee: F16.01 - Test Methods

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: F2328 − 17
Standard Test Method for
Determining Decarburization and Carburization in Hardened
and Tempered Threaded Steel Bolts, Screws, Studs, and
1
Nuts
This standard is issued under the fixed designation F2328; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers procedures for measuring,
E3Guide for Preparation of Metallographic Specimens
classifying, and determining the presence of decarburization
E384Test Method for Microindentation Hardness of Mate-
and carburization in the threaded section of hardened and
rials
temperedinchseriessteelbolts,screws,studs,nuts,andsimilar
F1789Terminology for F16 Mechanical Fasteners
parts which have been heated to facilitate fabrication or to
modify their mechanical properties. This test method is not
3. Terminology
intendedtoaddressproductswhichareintentionallycarburized
to achieve specific results.
3.1 Definitions:
3.1.1 carburization—process or result of increasing the
1.2 Two routine methods are described for measuring the
carbon content of the surface layers of the steel fastener
limits of and determining the presence of decarburization or
product.
carburization—the optical method and the microindentation
method 1. Either method is appropriate for routine examina- 3.1.2 decarburization—in accordance with Terminology
F1789,isalossofcarbonfromthesurfacelayerofthefastener,
tions. The microindentation method 2 shall be considered the
normally associated with heat treatment.
referee method.
3.1.3 gross decarburization—also known as complete
1.3 For the purpose of these tests, there are four classes of
decarburization, is characterized by a sufficient carbon loss to
hardened and tempered steel products for which specific
show only clearly defined ferrite grains.
measurements must be made with respect to their physical
properties. 3.1.4 partial decarburization—characterized as a loss of
carbon sufficient to cause a lighter shade of tempered marten-
1.4 Thevaluesstatedininch-poundunitsaretoberegarded
site than that of the immediately adjacent base metal, but as
asstandard.Nootherunitsofmeasurementareincludedinthis
being of insufficient carbon loss to show clearly defined ferrite
standard.
grains.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Significance and Use
responsibility of the user of this standard to establish appro-
4.1 Decarburization and carburization are two surface con-
priate safety, health, and environmental practices and deter-
ditions created, either intentionally or unintentionally, as with
mine the applicability of regulatory limitations prior to use.
a pre-existing condition created during the rod rolling process,
1.6 This international standard was developed in accor-
the rod/wire annealing process, or while heat treating threaded
dance with internationally recognized principles on standard-
steel products. Too much of either will adversely affect the
ization established in the Decision on Principles for the
safety and performance of the threaded product. Therefore,
Development of International Standards, Guides and Recom-
limits have been established for three different product groups:
mendations issued by the World Trade Organization Technical
the harder and greater the tensile strength of the product, the
Barriers to Trade (TBT) Committee.
more susceptible to failure the product becomes if these limits
are exceeded.
1
This test method is under the jurisdiction of ASTM Committee F16 on
2
Fasteners and is the direct responsibility of Subcommittee F16.01 on Test Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Sept. 1, 2017. Published September 2017. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2004. Last previous edition approved in 2014 as F2328–14. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F2328-17. 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
1

---------------------- Page: 1 ----------------------
F2328 − 17
4.2 When testing to a particular product specification that of any light-etching band of martensite defines the depth of
lists the dimensions and microindentation data to be used, that decarburization. Compare the image with Fig. 1 for the
data shall take precedence ove
...

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: F2328 − 14 F2328 − 17
Standard Test Method for
Determining Decarburization and Carburization in Hardened
and Tempered Threaded Steel Bolts, Screws, Studs, and
1
Nuts
This standard is issued under the fixed designation F2328; 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 test method covers procedures for measuring, classifying, and determining the presence of decarburization and
carburization in the threaded section of hardened and tempered inch series steel bolts, screws, studs, nuts, and similar parts which
have been heated to facilitate fabrication or to modify their mechanical properties. This test method is not intended to address
products which are intentionally carburized to achieve specific results.
1.2 Two routine methods are described for measuring the limits of and determining the presence of decarburization or
carburization—the optical method and the microindentation method 1. Either method is appropriate for routine examinations. The
microindentation method 2 shall be considered the referee method.
1.3 For the purpose of these tests, there are four classes of hardened and tempered steel products for which specific
measurements must be made with respect to their physical properties.
1.4 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this
standard.
1.5 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.
1.6 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
2.1 ASTM Standards:
E3 Guide for Preparation of Metallographic Specimens
E384 Test Method for Microindentation Hardness of Materials
F1789 Terminology for F16 Mechanical Fasteners
3. Terminology
3.1 Definitions:
3.1.1 carburization—process or result of increasing the carbon content of the surface layers of the steel fastener product.
3.1.2 decarburization—in accordance with Terminology F1789, is a loss of carbon from the surface layer of the fastener,
normally associated with heat treatment.
3.1.3 gross decarburization—also known as complete decarburization, is characterized by a sufficient carbon loss to show only
clearly defined ferrite grains.
3.1.4 partial decarburization—characterized as a loss of carbon sufficient to cause a lighter shade of tempered martensite than
that of the immediately adjacent base metal, but as being of insufficient carbon loss to show clearly defined ferrite grains.
1
This test method is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.01 on Test Methods.
Current edition approved Aug. 1, 2014Sept. 1, 2017. Published September 2014September 2017. Originally approved in 2004. Last previous edition approved in 20112014
as F2328 – 05F2328 – 14.(2011). DOI: 10.1520/F2328-14.10.1520/F2328-17.
2
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.
*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
1

---------------------- Page: 1 ----------------------
F2328 − 17
4. Significance and Use
4.1 Decarburization and carburization are two surface conditions created, either intentionally or unintentionally, as with a
pre-existing condition created during the rod rolling process, the rod/wire annealing process, or while heat treating threaded steel
products. Too much of either will adversely affect the safety and performance of the threaded product. Therefore, limits have been
established for three different product groups: the ha
...