... of machine parts heattreating(quenching,anneal, temper,normalizing),braze welding,smelting,copper bar annealing,bar copper heating before forging, ... . the lead manufacturer in china fastener line,Gem-Year Industrial Co., Ltd use our machine. 2.depth of quenching required more ... quenching 5.large-scale drill bit, cutting-tool welding 6.mallet alloy,red copper annealing,welding 7.metal smelting 8.gear, ...