·采用优质S2进口材料制造·硬度为HRC54-62,扭力比铬钒钢高出20%·表面为细砂丁镍处理·规格:1/16-5/64-3/32-7/64-1/8-9/64-5/32-3/16-7/32-1/4-5/16-3/8