vacuum positive pressure tempering furnace Models: WZH-20, WZH-30, WZH-45, and WZH-60.It is mainly used for vacuum tempering of high-speed steel, alloy tool steel, bearing steel, stainless steel and special alloys. It can also be used for recrystallization annealing and aging of non-ferrous metal. WZH series vacuum positive pressure tempering furnace