Process

Unique in the world, the Stelmi hard chromium plating process is a 24 hour a day continuous horizontal operation. Using an automated material handling system, which also transfers the required electrical contact to each bar, the bars advance and rotate, driven one by one through a series of circular anodes in the chrome plating machines. The ground and polished bars enter the machine from one side and exit, fully plated, from the other. The bars are completely plated up to the end, contrary to any of the conventional plating processes

In conventional plating methods, the chromium plating operation takes place on stationary bars hung horizontally on a large frame or rack. The dipping rack carrying the bars is submerged in the bath for a period of time. The bars are mechanically and electrically fixed to the rack which, in turn, is connected to the cathode. The anodes are placed on the long side of the tank; there is no way to create an electric field concentric to the bars and this leads to thickness variations in the chromium overlay. Conventional plating methods leave unplated areas on both ends of each bar length and the fixed electrical contact causes unwelcome heavy plate near the unplated ends. None of these problems exist with the Stelmi process, the chromium plating is done with a series of circular anodes, and each bar continuously advances and rotates through the anodes, so that a completely homogeneous and dimensionally uniform chrome layer is guaranteed.

The continuous process gives Stelmi chrome plated bars unparalleled corrosion resistance, proven in field use and in neutral salt spray testing. The traditional manufacturers of chrome plated bars enhance their corrosion resistance by buffing the surface with various types of "wax". Stelmi hard chrome plated bars offer better corrosion resistance without any use of these temporary coatings.