ASTM F1941/F1941M-15
(Specification)Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric
Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric
ABSTRACT
This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded fasteners with metric 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. The coating material, coating thickness, chromate finish, and trivalent chromite finish shall be selected and designated. The electrodeposited coating shall cover all surfaces and shall meet the following requirements: the coating metal deposit shall be bright or semibright, smooth, fine grained, adherent and uniform in appearance; the coating shall be free of blisters, pits, nodules, roughness, cracks, unplated areas, and other defects that will affect the function of the coating; and the coating shall not be stained, discolored or exhibit any evidence of white or red corrosion products. Slight discoloration that results from baking, drying, or electrode contact during rack-plating, or all of these, as well as slight staining that results from rinsing shall not be cause for rejection. Corrosion resistance and embrittlement of coatings shall be determined by performing mechanical tests.
SCOPE
1.1 This specification covers application, performance and dimensional requirements for electrodeposited coatings on threaded fasteners with unified inch and metric screw threads, but it may also be applied to other threaded parts and non-threaded parts such as washers and pins. It specifies coating thickness, supplementary hexavalent chromate or non-hexavalent conversion 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 and SI metric units. 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 to the standard.
1.3 Terms used in this specification are defined in Terminology F1789.
1.4 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/F1941M −15
Standard Specification for
Electrodeposited Coatings on Mechanical Fasteners, Inch
1
and Metric
ThisstandardisissuedunderthefixeddesignationF1941/F1941M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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.
INTRODUCTION
This specification covers the coating of steel unified inch and metric mechanical fasteners by
electrodeposition. The properties of the coatings shall conform to the ASTM standards for the
individual finishes. This standard shall be used in place of ASTM B633 for mechanical fasteners.
Coating thickness values are based on standard tolerances for inch and metric external threads.The
coating must not cause the basic thread size to be transgressed by either the internal or external
threads.ThemethodofdesignatinginchcoatedthreadsshallcomplywithASMEB1.1andISO965-1,
ISO 965-2, and ISO 965-3 for ISO metric coated threads.
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
hardnessabove39HRC.Althoughthisriskcanbemanagedbyselectingrawmaterialssuitableforthe
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* 1.3 Terms used in this specification are defined in Termi-
nology F1789.
1.1 This specification covers application, performance and
1.4 The following precautionary statement pertains to the
dimensional requirements for electrodeposited coatings on
test method portion only, Section 9, of this specification: This
threaded fasteners with unified inch and metric screw threads,
standard does not purport to address all of the safety concerns,
but it may also be applied to other threaded parts and
if any, associated with its use. It is the responsibility of the user
non-threaded parts such as washers and pins. It specifies
of this standard to establish appropriate safety and health
coating thickness, supplementary hexavalent chromate or non-
practices and determine the applicability of regulatory limita-
hexavalent conversion finishes, corrosion resistance, precau-
tions prior to use.
tions for managing the risk of hydrogen embrittlement and
hydrogen embrittlement relief for high-strength and surface-
2. Referenced Documents
hardened fasteners. It also highlights the differences between
2
2.1 ASTM Standards:
barrel and rack plating and makes recommendations as to the
applicability of each process. B117Practice for Operating Salt Spray (Fog) Apparatus
B487Test Method for Measurement of Metal and Oxide
1.2 The values stated in inch-pound units and SI metric
Coating Thickness by Microscopical Examination of
units. The values stated in each system may not be exact
Cross Section
equivalents; therefore each system shall be used independently
B499Test Method for Measurement of CoatingThicknesses
of the other. Combining values from the two systems may
by the Magnetic Method: Nonmagnetic Coatings on
result in non-conformance to the standard.
Magnetic Basis Metals
B504Test Method for Measurement of Thickness of Metal-
lic Coatings by the Coulometric Method
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 Sept. 1, 2015. Published October 2015. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1998. Last previous edition approved in 2010 as F1941–10. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F1941_F1941M-15 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/F1941M−15
NOTE 1—Black dot (•) indicates test surface.
FIG. 1Significant Surfaces on Externally Threaded Fasteners
6
B567Test Method for Measurement of Coating Thickness 2.5 ISO Standards:
by the Beta Backscatter Method ISO 965-1ISO General Purpose Metric Screw Threads –
B568Test Method for Measurement of Coating Thickness Tolerances – Part 1: Principles and Basic Data
by X-Ray Spectrometry ISO 965-2ISO General Purpose Metric Screw Threads –
B
...
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 − 10 F1941/F1941M − 15
Standard Specification for
Electrodeposited Coatings on Threaded Fasteners (Unified
Inch Screw Threads (UN/UNR))Mechanical Fasteners, Inch
1
and Metric
This standard is issued under the fixed designation F1941;F1941/F1941M; 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 and metric mechanical
fasteners by electrodeposition. The properties of the coatings shall conform to the ASTM standards for
the individual finishes listed.finishes. This standard shall be used in place of ASTM B633 for
mechanical fasteners.
Coating thickness values are based on thestandard tolerances for 1Ainch and 2A external Unified
Inch Screw Threads. metric external threads. The coating must not cause the basic thread size to be
transgressed by either the internal or external threads. The method of designating inch coated threads
shall comply with ASME B1.1.B1.1 and ISO 965-1, ISO 965-2, and ISO 965-3 for ISO metric coated
threads.
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. above 39 HRC. 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. and metric screw threads, but it may also be applied to other threaded parts and
non-threaded parts such as washers and pins. It specifies coating thickness, supplementary hexavalent chromate or non-hexavalent
passivateconversion 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. No other units of measurement are included in this
and SI metric units. 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 to the standard.
1.3 Terms used in this specification are defined in Terminology F1789.
1.4 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.
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 Dec. 15, 2010Sept. 1, 2015. Published January 2011October 2015. Originally approved in 1998. Last previous edition approved in 20072010
as F1941 – 07.F1941 – 10. DOI: 10.1520/F1941-10.10.1520/F1941_F1941M-15
*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/F1941M − 15
NOTE 1—Black dot (•) indicates test surface.
FIG. 1 Significant Surfaces on Externally Threaded Fasteners
2. Referenced Documents
2
2.1 ASTM Standards:
B117 Practice for Operating Salt Spray (Fog) Apparatus
B487 Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section
B499 Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis
Metals
B504 Te
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.