quality/ ISO9001,zhuzhou601 1) Tapered connection: 6°, 7°, 12° 2) Threaded connection: R22, R25, R28, R32, R38, T38, T45, T51 3) Diameter: 30-127mm 4) Best Alloy steel 5.We are able to supply all kinds of rock drilling hammers,bits and related products, the products are mianly used in mining,coaling,metaling,stoning and etc. button bits