SSSSP（镀硬铬产品，镀层厚度 t≧3μm）
QD51(相当于SUS440C)
≧HRC56
g6 h5
3, 4, 5, 6, 8, 10, 12, 13, 15, 16, 20, 25, 30, 35, 40, 50