10 5/8" inch 270mm drag bit/pdc drag drill bit for water well drilling 1.ISO9001:2000 2.Wings/Blade: 3, 4 ... rock formation f≤6, like mudstone, shale, sandstone, etc. mainly used for drain hole, grouting hole, geological and hydrology drilling, Usually ... of polycrystalline diamond layer sintered with tungsten carbide substrates. 10 5/8" inch 270mm drag bit/pdc drag drill bit for ...