The ISO 6158-1984 standard "Chromium platings for engineering use in metal coatings" mainly specifies the representation method of chromium platings for engineering use, the information to be provided when processing and ordering, the heat treatment process specifications before and after plating, platings mass requirements and test methods, etc. It is suitable for engineering chromium platings with or without bottom platings on ferrous metal or non-ferrous metal substrates, often referred to as "thick chromium" or "hard chromium" layers. The standard does not cover thin chromium surfaces for protective decoration purposes. The details include the bonding strength, surface roughness, thickness measurement, corrosion resistance test and other requirements of the chromium layer to ensure the mass and performance of chromium platings in engineering applications.