Heavy duty tungsten carbide tipped core drills 110mm cutting depth. For cutting fast clean holes in, concrete, aerated block. light to medium density bricks, blocks and masonry.82MMThe concrete hole saw kit made of tungsten steel and alloy, high-frequency welding technology, welding openings is very strong, smooth inside and outside welding mouth. Ultra-sturdiness and durable, easy to opearation, and long service life.