(1) has excellent machinability, and hardened, the size is extremely stable, hardened, the surface has high hardness. 
 (2) with high toughness, good abrasion resistance and easy so the forging and quenching. 
 (3) may be suitable for widespread use in the cutting, cold stamping and forming tools; 
 Such as notches knife mold, cold stamping die, a variety of gauges, reamers, sleeves and a small plastic mold mold parts.