ASTM F1941-07
(Specification)Standard Specification for Electrodeposited Coatings on Threaded Fasteners (Unified Inch Screw Threads (UN/UNR))
Standard Specification for Electrodeposited Coatings on Threaded Fasteners (Unified Inch Screw Threads (UN/UNR))
ABSTRACT
This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded fasteners with unified inch screw threads. It specifies coating thickness, supplementary hexavalent chromate or trivalent chromite finishes, corrosion resistance, precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for high-strength and surface-hardened fasteners. The electrodeposited coating as ordered shall cover all surfaces and shall meet the requirements prescribed. Coated fasteners, when tested by continuous exposure to neutral salt spray shall show neither corrosion products of coatings (white corrosion) nor basis metal corrosion products (red rust) at the end of the test period. The coating thickness, embrittlement, corrosion resistance, and trivalent chromite finish shall be tested to meet the requirements prescribed.
SCOPE
1.1 This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded fasteners with unified inch screw threads. It specifies coating thickness, supplementary hexavalent chromate or trivalent chromite finishes, corrosion resistance, precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for high-strength and surface-hardened fasteners. It also highlights the differences between barrel and rack plating and makes recommendations as to the applicability of each process.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 The following precautionary statement pertains to the test method portion only, Section 9, 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.
General Information
Relations
Buy Standard
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: F1941 – 07
Standard Specification for
Electrodeposited Coatings on Threaded Fasteners (Unified
1
Inch Screw Threads (UN/UNR))
This standard is issued under the fixed designation F1941; 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.
INTRODUCTION
This specification covers the coating of steel unified inch screw threaded fasteners by electrodepo-
sition. The properties of the coatings shall conform to theASTM standards for the individual finishes
listed.
Coating thickness values are based on the tolerances for 1A and 2A external Unified Inch Screw
Threads. The coating must not cause the basic thread size to be transgressed by either the internal or
external threads. The method of designating coated threads shall comply with ASME B1.1.
With normal methods for depositing metallic coatings from aqueous solutions, there is a risk of
delayed failure due to hydrogen embrittlement for case hardened fasteners and fasteners having a
hardness 40 HRC or above.Although this risk can be managed by selecting raw materials suitable for
the application of electrodeposited coatings and by using modern methods of surface treatment and
post heat-treatment (baking), the risk of hydrogen embrittlement cannot be completely eliminated.
Therefore, the application of a metallic coating by electrodeposition is not recommended for such
fasteners.
1. Scope* 2. Referenced Documents
2
1.1 This specification covers application, performance and 2.1 ASTM Standards:
dimensional requirements for electrodeposited coatings on B117 Practice for Operating Salt Spray (Fog) Apparatus
threaded fasteners with unified inch screw threads. It specifies B487 Test Method for Measurement of Metal and Oxide
coatingthickness,supplementaryhexavalentchromateortriva- CoatingThicknessbyMicroscopicalExaminationofCross
lent chromite finishes, corrosion resistance, precautions for Section
managing the risk of hydrogen embrittlement and hydrogen B499 Test Method for Measurement of Coating Thick-
embrittlement relief for high-strength and surface-hardened nessesbytheMagneticMethod:NonmagneticCoatingson
fasteners. It also highlights the differences between barrel and Magnetic Basis Metals
rackplatingandmakesrecommendationsastotheapplicability B504 Test Method for Measurement of Thickness of Me-
of each process. tallic Coatings by the Coulometric Method
1.2 The values stated in inch-pound units are to be regarded B567 Test Method for Measurement of Coating Thickness
as standard. No other units of measurement are included in this by the Beta Backscatter Method
standard. B568 Test Method for Measurement of Coating Thickness
1.3 The following precautionary statement pertains to the by X-Ray Spectrometry
test method portion only, Section 9, of this specification: This B659 Guide for Measuring Thickness of Metallic and Inor-
standard does not purport to address all of the safety concerns, ganic Coatings
if any, associated with its use. It is the responsibility of the user D6492 Practice for Detection of Hexavalent Chromium On
of this standard to establish appropriate safety and health Zinc and Zinc/Aluminum Alloy Coated Steel
practices and determine the applicability of regulatory limita- E376 Practice for Measuring Coating Thickness by
tions prior to use. Magnetic-FieldorEddy-Current(Electromagnetic)Exami-
nation Methods
1
This specification is under the jurisdiction of ASTM Committee F16 on
Fasteners and is the direct responsibility of Subcommittee F16.03 on Coatings on
2
Fasteners.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Dec. 1, 2007. Published January 2008. Originally
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1998. Last previous edition approved in 2006 as F1941 – 00 (2006).
Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/F1941-07.
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 ----------------------
F1941 – 07
NOTE 1—Black dot (•) indicates test surface.
FIG. 1 Significant Surfaces on Externally Threaded Fasteners
F606 Test Methods for Determining the Mechanical Prop-
erties of Externally and Internally Threaded Fasteners,
Washers, Direct Tension Indicators, and Rivets
F1470 Practice for Fastener Sampling for Specified Me-
chanical Properties and Performance Inspection
NOTE 1—Black dot (•) indicates test surface.
F1624 Test Method
...
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:F1941–00 (Reapproved 2006) Designation: F 1941 – 07
Standard Specification for
Electrodeposited Coatings on Threaded Fasteners (Unified
1
Inch Screw Threads (UN/UNR))
This standard is issued under the fixed designation F 1941; 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 (e) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This specification covers the coating of steel unified inch screw threaded fasteners by electrodepo-
sition. The properties of the coatings shall conform to theASTM standards for the individual finishes
listed.
Coating thickness values are based on the tolerances for 1A and 2A external Unified Inch Screw
Threads. The coating must not cause the basic thread size to be transgressed by either the internal or
external threads. The method of designating coated threads shall comply with ASME B1.1.
With normal methods for depositing metallic coatings from aqueous solutions, there is a risk of
delayed failure due to hydrogen embrittlement for case hardened fasteners and fasteners having a
hardness 40 HRC or above.Although this risk can be managed by selecting raw materials suitable for
the application of electrodeposited coatings and by using modern methods of surface treatment and
post heat-treatment (baking), the risk of hydrogen embrittlement cannot be completely eliminated.
Therefore, the application of a metallic coating by electrodeposition is not recommended for such
fasteners.
1. Scope*
1.1 This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded
fasteners with unified inch screw threads. It specifies coating thickness, supplementary hexavalent chromate or trivalent chromite
finishes, corrosion resistance, precautions for managing the risk of hydrogen embrittlement and hydrogen embrittlement relief for
high-strength and surface-hardened fasteners. It also highlights the differences between barrel and rack plating and makes
recommendations as to the applicability of each process.
1.2 ThevaluesstatedinSIinch-poundunitsaretoberegardedasthestandard.Thevaluesgiveninparenthesesaremathematical
conversions to SI units that are provided for information only and are not considered standard.
1.3 The following precautionary statement pertains to the test method portion only, Section 9, 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.
2. Referenced Documents
2
2.1 ASTM Standards:
B 117 Practice for Operating Salt Spray (Fog) Apparatus
B 487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section
B 499 Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic
Basis Metals
B 504 Test Method for Measurement of Thickness of Metallic Coatings by the Coulometric Method
B 567 Test Method for Measurement of Coating Thickness by the Beta Backscatter Method
B 568 Test Method for Measurement of Coating Thickness by X-Ray Spectrometry
B 659 Guide for Measuring Thickness of Metallic and Inorganic Coatings
1
This specification is under the jurisdiction of ASTM Committee F16 on Fasteners and is the direct responsibility of Subcommittee F16.03 on Coatings on Fasteners .
Current edition approved June 1, 2006. Published June 2006. Originally approved in 1998. Last previous edition approved in 2000 as F1941–00.
Current edition approved Dec. 1, 2007. Published January 2008. Originally approved in 1998. Last previous edition approved in 2006 as F 1941 – 00 (2006).
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. 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 ----------------------
F1941–07
NOTE 1—Black dot (•) indicates test surface.
FIG. 1 Significant Surfaces on Externally Threaded Fasteners
D 64
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.