Drill Bits Diamond Core Drill Bit SetThis high quality Drill Bit Set contains 16 pieces of bits of various sizes to meet different drilling needs. The bits are perfect for use with electric core drills for drilling on granite, hard stone, concrete, reinforced concrete, and other hard surfaces. The durable construction will ensure smooth operation of the drills. Delivery includes 16 pieces diamond core drill bits of the following diameters: 26 mm, 32 mm, 44 mm, 50 mm, 63 mm, 71 mm, 82 mm,