Best Seller | QEP 10571 Drill Bit Set Diamond Tipped SDS-max QEP 5/16 Porcelain Diamond Drill Bit is ideal for cutting 5/16 holes through ceramic glass marble porcelain and granite. It includes a drill guide and water delivery system for use with wet drilling only. The drill bit has a fixed blade and a straight... more | | $18.28 $15.62 FREE shipping go to store |