GMW GMW15613 PDF

This specification covers the basic requirements for nickel chromium plating on stainless steel. Nickel-chrome plating on other metals is covered by GMW14672.

Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose/Material Description.

Plating to this specification is subdivided into three (3) six performance classes. Classes A, C, and E are plated using hexavalent chromium chemistries. Classes B, D, and F are plated using trivalent chromium chemistries.

Symbols.

Not applicable.

Applicability.

Code A (Hexavalent) and Code B (Trivalent).

Primarily applicable to exterior fasteners, moldings and other trims made of austenitic stainless steel (300 series per SAE J405 or regional equivalent). The stainless substrates may not need buffing and provide excellent color match for surrounding plated trim. Coating consists of four (4) layers; a woods nickel strike (necessary for proper adhesion of plating to stainless), bright or satin nickel, microporous nickel, and chromium.

Code C (Hexavalent) and Code D (Trivalent).

Chrome flash finish for color match only and may be used for exterior or interior applications.

Code E (Hexavalent) and Code F (Trivalent).

Primarily applicable to exterior and interior moldings and other trims made of Ferritic Stainless Steel (Types 434 – Unified Numbering System (UNS) S43400 and 436 - UNS S43600). The stainless steel substrates may not need buffing and provide excellent color match for surrounding plated trim. Coating consists of four (4) layers which include a woods nickel strike, bright or satin nickel, microporous nickel, and chromium.

Remarks.

Type 434 and Type 436 stainless steel, as well as those used with Code C and Code D, (chrome flash), normally require mechanical finishing (pre-buff strip, part buffing) to meet component appearance requirements. The mechanical finishing requirements shall be agreed upon between stainless steel supplier and user.