This process refers to the production activity of removing 1kg of steel through machining, excluding the machining processes for butterfly valves and ball valves. If the weight of steel removed during machining is not clearly defined, an average assumption of "0.142kg of steel waste generated per 1kg of final product produced" may be used. The data originate from the production processes of cylinders, shafts, rollers, drill bits, and other mechanical and electrical equipment accessories, excluding valve production.