BS 7371-3:2009 PDF

Scope: This Part of BS 7371 specifies requirements for coatings applied by the electrolysis of solutions of zinc. NOTE The coatings consist principally of zinc and can be lubricated to give controlled torque/clamping force properties when required (see, for example, BS 7371-2). In addition to the requirements in this Part of BS 7371, the requirements in BS 7371-1 which are applicable to zinc electroplated coatings apply. This Part of BS 7371 also specifies requirements for: a) the coating thickness; b) the type of conversion treatment or topcoat to be applied; c) quality assessment of the corrosion resistance of unused coated parts when subjected to neutral salt spray testing (for example BS EN ISO 9227); and d) an adhesion test. Zinc electroplated coatings covered by this Part of BS 7371 are for use on fasteners and accessories where the following apply: 1) A coating giving galvanic protection is required for ferrous fasteners. 2) A substrate is required to improve the corrosion resistance of subsequent coatings on ferrous fasteners, e.g. organic. 3) The risk of hydrogen embrittlement of high tensile steel fasteners is acceptable.

BS 7371-3:2009 Referenced Document

BS 3643-1 ISO metric screw threads Part 1 : Principles and basic data
BS 3643-2 ISO metric screw threads Part 2 : Specification for selected limits of size
BS 7371-1 Coatings on metal fasteners – Part 1: Specification for general requirements and selection guidelines
BS EN ISO 2177 Metallic coatings - Measurement of coating thickness - Coulometric method by anodic dissolution
BS EN ISO 2819 Metallic coatings on metallic substrates. Electrodeposited and chemically deposited coatings. Review of methods available for testing adhesion*， 2020-02-25 Update
BS EN ISO 3497 Metallic coatings - Measurement of coating thickness - X-ray spectrometric methods
BS EN ISO 3882 Metallic and other inorganic coatings. Review of methods of measurement of thickness*， 2024-01-31 Update
BS EN ISO 9227 Corrosion tests in artificial atmospheres. Salt spray tests*， 2022-11-25 Update

2009 BS 7371-3:2009 Coatings on metal fasteners – Part 3: Specifications for electroplated zinc coatings
1993 BS 7371-3:1993 Coatings on metal fasteners. Specification for electroplated zinc and cadmium coatings