guide bushing 1,Materials: HSS M2, SKH9, SKD11 2,Tolerance: less than ... ,Working life: 20,0000times 4,8-10 work days guide bushing Type circular, Square Header , hexagonal , R-shaped…MaterialHSS M-2 ... (Mainland)Machine TypePunching Machine Please specify the details of guide bushing as follows when you inquiry1,The shape of punches you ...