GB/T 5267.2-2017

This part of GB/T 5267 specifies the technical requirements for non-electrolytic zinc flake coatings on steel fasteners. This part applies to the following coatings: -- with or without hexavalent chromium; -- with or without surface coatings; -- with or without lubrication (integrated lubrication and/or additional lubrication). Note: Certain chemical elements are restricted or prohibited for use by some national regulations. When dealing with relevant countries or regions, attention should be paid. This part applies to ISO metric threaded bolts, screws, double-headed studs and nuts, non-ISO metric threaded fasteners, and non-threaded fasteners such as washers, pins, clamps, etc. Note: Coatings that comply with this part, especially those used on high-strength fasteners (≥ 1,000 MPa), should avoid the risk of internal hydrogen embrittlement (see 4.4). For design and installation information of coated fasteners, please refer to Appendix A. This part does not specify the weldability or coating performance of fasteners, and it is not applicable to mechanical galvanizing.