Precast Diamond Core Bits for Reinforced Concrete, Brick, Stone, Plank, Hard Materials 2"- 6"Laser Welded Diamond Core Bits Designed to Drill Precast Concrete & Reinforced Concrete with High PSI Featuring High Diamond Concentration V Segments Precision Alignment for Precast Cable and Pandeck Drilling Wet Drilling Diamond Core Bits 1 1 4" 7 Thread 14" Length Global Diamond Pros diamond core bits are available in a wide variety of sizes with a standard 14 inch long barrel. These precast bits have been tested on concrete and concrete with rebar;