... inch 311mm drag bit/pdc drag drill bit for water well drilling 1.ISO9001:2000 2.Wings/Blade: 3, 4 ABOUT ... of diamond products,has taken the lead in mining drilling,metal cutting and grinding processes 3 big fields.ABOUT ... used for drain hole, grouting hole, geological and hydrology drilling, Usually drag bits are three wings, while sometime people ... drag bit/pdc drag drill bit for water well drilling