GMW GMW3200 PDF

1 Scope

This specification covers the basic requirements for Sn-Zn electroplate on steel substrates mating to aluminum, steel and cast iron with provisions for supplementary treatments and corrosion resistance. This plating is intended for grounding purposes. Alloy composition shall be a range of (75 ± 10) % Sn and the remainder Zn. Minimum recommended plating thickness shall be 8 µm. Higher or lower plating thickness may be specified at the discretion of the user. Note: Verification of alloy composition shall be by XRF (X-ray Fluorescence) or AA (Atomic Absorption) using standards and procedure approved by the chemical supplier or equipment manufacturer. 1.1 Material Description. The material approved to this specification covers Sn-Zn electroplate plus a subsequent protective treatment. This coating system must be free of hexavalent chromium with no hexavalent chromium in final product per the requirements of GMW3059. GMW3034 shall be used as a referee test. 1.1.1 Material Identificat