... , with PDC cutter inserts on the blades,they are applied to rock formation f≤6, like mudstone, shale, sandstone, etc. mainly ... can meet your all request. Our diameter is from 75mm to 270mm,any special design is available upon customers’ request.ADVANTAGESISO9001 ... made of polycrystalline diamond layer sintered with tungsten carbide substrates. 11 1/2" inch 292mm drag bit/pdc drag drill bit for water ...