... ironstone, chert, abrasive rock etc. Including impregnated diamond core bit, surface-set diamond bit, reaming shells, casing bit, casing shoe ... are used A to set with synthetic, natural or polycrystalline diamond. It's used for drilling in soft to medium ... minisite.productShow(); oProductShow.init( { 'aImgSrc': aBigImageSrc } ); } )(); Surface set diamond core bit NQ, HQ, PQ, NQTT, HQWL, T2, T6, NMLC ...