” Hard” Chrome plate also known as “Industrial” Chrome plate is applied to errous and nonferrous materials to improve resistance to wear and abrasion, reduce the coefficient of friction and prevent seizing and galling. Hard Chrome plate can also be used to restore dimensions of undersized parts.
The standard thickness for Chrome plate in nonsalvage applications is 0.2 – 0.6 mil. AT lower thickness (i.e. 1 mil. or less) the Chrome can usually be plated to specific tolerances depending on the configuration of the part. Thicknesses over 1 mil. generally require the plating to be applied thicker than needed and then ground to size.
Virtually any RMs can be achieved using the Chrome plating process. For best results, the area to be coated should be completely finished prior to processing. For surface finishes finer that 6 RMS post plate lapping or polishing may be required.
The hardness of the coating is 65-68 Rc. Hardness should be measured on a cross section using suitable micro-hardness tester,
The resistance of the coating to corrosion is dependent upon such factors as basic metal, RHR (Roughness Height Reading), surface porosity of basic metal, micro-inch finish, corrosive media and thickness coating. Although Chrome plate does offer some corrosion resistance, it is not the most corrosion resistant of the available coatings. For applications requiring hardness and corrosion
resistance, a layer of various non-corrosive coatings can be applied prior to Chrome plate operation.
FEDERAL AND MILITARY REQUIRMENTS
The Hard Chrome Plate meets or exceeds QQ-C-320B and MIL-C-23422D