ASTM F1941_F1941M-16R25
Standard Specification for Electrodeposited Coatings on Mechanical Fasteners, Inch and Metric
| Označení normy: | ASTM F1941_F1941M-16R25 |
| Vydáno: | 01.01.2025 |
| Status: | Active |
| Počet stran: | 14 |
| Sekce: | 01.09 |
| Označení: | baking; chromium; conversion coating; corrosion; electroplating; hydrogen embrittlement; protection; resistance; sealant; thickness; topcoat; zinc; |
| ASTM označení: | ASTM F1941/F1941M |
| Nahrazuje: | F1941_F1941M-16 |
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.
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 coatings, 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 either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.
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, health, and environmental 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.