... heating treatment, parts surface hardening, tempering, annealing, etc.B: metal brazing, high-frequency brazing, pan bottom brazing, tool head brazing ... warm bending, high frequency shrinkage fitting, heat enveloping, heat sealing, metal desiccating, nut inserting, rotor inserting,etc.D: precious metals melting ... Machines have achieved widespread recognition in the field of precious metal casting.