This specification establishes the requirements for electrodeposited zinc coatings applied to iron or steel articles for corrosion protection purposes. Electrodeposited zinc-coated steel wires or sheets are not covered here. The coatings shall be provided in four standard thickness classes in the as-plated condition or with one of three types of supplementary finishes. The surfaces of the articles shall under go pre-plating basis metal cleaning, pre- and post-coating treatment for reducing the risk of hydrogen embrittlement, and reactivation and supplementary treatments. Coatings should be sampled, prepared, tested and conform accordingly to specified requirements as to appearance (luster and workmanship), thickness, adhesion, corrosion resistance, and hydrogen embrittlement.

1.1 This specification covers requirements for electrodeposited zinc coatings applied to iron or steel articles to protect them from corrosion. It does not cover electrodeposited zinc-coated steel wire or sheets (see Specification A 591/A 591M for sheets).

1.2 The coatings are provided in four standard thickness classes (4.1), in the as-plated condition or with one of three types of supplementary finish (4.2).

1.3 High strength metals, unless otherwise specified, including high strength steels having a tensile strength greater than 1700 MPa (247 ksi Rc 46) shall not be electroplated.

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.

1.4 This standard has been revised to address RoHS requirements that seek to limit the exposure of workers and the public from exposure to toxic metals. Additional types have been added to permit non-chromate passivate treatments to be used in replacement of hexavalent chromium.