SKH-57 
 Main Ingredients% 
 C carbon Si Si Mn Cr (chromium) the W W V (vanadium) of Mo Mo VP P S sulfur 0.85 0.45 0.45 4.00 5.80 1.80 4.80 0.03 0.01 
 Forging: 1.100 ~ 900 ° C annealing: heating to 800-850 ° C, stay at this temperature for two to four hours, any of its getting cold in the furnace. 
 Quenching: the first pre-heated to 550-600 ° C, heated to 950 ℃, and then heated to a: 1,220 ~ 1250 ° C; b: 1,200 ℃ ~~ 1230 ℃. Hardened in oil, but the oil temperature must be moisturizing 40-60 ° C (a. General Tools; (b) the form of complex needs toughness tools) 
 Tempering: heating to 550-570 ° C, to stay at this temperature and then cooling in still air, tempering must be repeated secondary 
 Hardness: HRC63 ℃ above. 
 Uses: This high-speed steel, tungsten steel, it is appropriate to manufacturing powerful cutting wear and impact resistance a variety of tools, the senior dies, screw mold than the required toughness and shape of the complex tool, milling cutter, drill, etc.