Dri Vacuum Drill Bits DRI-8 are optimal for coring block.

Dri Vacuum Drill Bits feature a large threaded adapter with 1-1/4″ 7 threads/inch for maximum-size vacuum holes. The non-slotted tube design ensures suction at the cutting tip of the drill bit, while the reduced core travel length (10″) allows for easier start-up and low side run-out.