BS EN ISO 4042:2022 - Page 3

Fasteners. Electroplated coating systems. | Status: Current, Under review

1 Scope This document specifies requirements for steel fasteners with electroplated coatings and coating systems. The requirements related to dimensional properties also apply to fasteners made of copper or copper alloys. It also specifies requirements and gives recommendations to minimize the risk of hydrogen embrittlement, see 4.4 and Annex B. It mainly applies to fasteners with zinc and zinc alloy coating systems (zinc, zinc-nickel, zinc-iron) and cadmium, primarily intended for corrosion protection and other functional properties:

• — with or without conversion coating,
• — with or without sealant,
• — with or without top coat,
• — with or without lubricant (integral lubricant and/or subsequently added lubricant).

Specifications for other electroplated coatings and coating systems (tin, tin-zinc, copper-tin, copper-silver, copper, silver, copper-zinc, nickel, nickel-chromium, copper-nickel, copper-nickel-chromium) are included in this document only for dimensional requirements related to fasteners with ISO metric threads. The requirements of this document for electroplated fasteners take precedence over other documents dealing with electroplating. This document applies to steel bolts, screws, studs and nuts with ISO metric thread, to other threaded fasteners and to non-threaded fasteners such as washers, pins, clips and rivets.

NOTE Electroplating is also applied to stainless steel fasteners, e.g. for the purpose of lubrication in order to avoid galling.

Information for design and assembly of coated fasteners is given in Annex A. This document does not specify requirements for properties such as weldability or paintability.