Drill rod_ Casing pipe in 1.5m and 3m NQ, HQ, PQ T2, T6, LTK NMLC, HMLC NW, HW, PW, NWT, HWF Specialisted in producing varies kinds of diamond core bits in different size, which are used in shale, sandstone, limestone, marble, dolomite, schist, granite, quartz, ironstone, chert, abrasive rock etc. Including impregnated diamond core bit, surface-set diamond bit, reaming shells, casing bit, casing ...