Concrete Core Bit - Diamond Core Bit - Wet Drilling Core Bits Laser Welded for Hard Concrete - Masonry - Reinforced Concrete Core DrillingDiamond Core Bits for Concrete, Reinforced Concrete, Masonry, Stone & more! Wet Core Drilling Diamond Core Bits 1 1 4" 7 Thread 14" Barrel Length For the most reliable core drilling performance, trust Global Diamond Pros' double laser welded ultimate series core bits. Made with high diamond concentration segments, our bits provide a smooth drilling experience and extended lifespan when working with hard materials like concrete, brick, and granite.