LASER WELDING DIAMOND CORE DRILL-DRY . FEATURES: All main sizes for extraction and ventilation work. Core drill segments are laser welded so will withstand higher temperatures and last longer. These core bits are designed to cut smooth, round holes through a range of different masonry with out any material breakout. Perfect sizes for han basin waste pipes, overflow pipes, shower and bath waste pipes, extraction vents for boilers and dryers. Always use rotary drilling mode when using these cutters. Cores are for dry cutting only. Application: Medium/Hard Brick,Medium/Hard Concrete Blocks Facing Bricks,Hard & Coarse Sandstone,Soft Slate Breeze Blocks,Lignacite Blocks