ASTM F1941/F1941M-15 - 1.9.2015
 
1. 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.

 
2. Referenced Documents

B117-19

Standard Practice for Operating Salt Spray (Fog) Apparatus

B633-23

Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel

IFI-142

Hydrogen Embrittlement Risk Management

B18.6.3

B1.16M

Gages and Gaging for Metric M Screw Threads

B1.1

Unified Inch Screw Threads (UN and UNR Thread Form)

F2078-22

Standard Terminology Relating to Hydrogen Embrittlement Testing

F1624-12(2018)

Standard Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique

F1940-07a(2019)

Standard Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners (Includes all amendments and changes 9/17/2019).

F1789-23

Standard Terminology for F16 Mechanical Fasteners

F1470-24

Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection

B504-90(2023)

Standard Test Method for Measurement of Thickness of Metallic Coatings by the Coulometric Method

B499-09(2021)e1

Standard Test Method for Measurement of Coating Thicknesses by the Magnetic Method: Nonmagnetic Coatings on Magnetic Basis Metals (Includes all amendments and changes 5/18/2021).

B487-20

Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section

F788-20

Standard Specification for Surface Discontinuities of Bolts, Screws, Studs, and Rivets, Inch and Metric Series

F606/F606M-21

Standard Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, Direct Tension Indicators, and Rivets

B659-90(2021)

Standard Guide for Measuring Thickness of Metallic and Inorganic Coatings

B567-98(2021)

Standard Test Method for Measurement of Coating Thickness by the Beta Backscatter Method

B568-98(2021)

Standard Test Method for Measurement of Coating Thickness by X-Ray Spectrometry

D6492-99(2022)

Standard Practice for Detection of Hexavalent Chromium On Zinc and Zinc/Aluminum Alloy Coated Steel

E376-19

Standard Practice for Measuring Coating Thickness by Magnetic-Field or Eddy Current (Electromagnetic) Testing Methods

F519-23

Standard Test Method for Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service Environments