1. Qualified for big parts and assemblies. 2. Different materials: copper, CRS, HRS, stainless steel, Al, al-mag alloy, etc. 3. Different surface treatment: zinc, copper, chrome, nickel plated, powder coated, etc. 4. Parts or assemblies used for many applications: auto parts, marine parts, office equipment, department store equipment. 5. Strictest test for each parts and assembly.