Tungsten Carbide Tip. Finish: Sand Blasted. -Specially designed ground tungsten carbide tip. -Heat treated to increase the life span of the drill bit. -Hexagon shank stops slippage in the drill chuck increasing speed and efficiency. -Sand blast finish for increased durability. -Reduced shank to 12.7mm from size 16mm diameter upwards. -Suitable for drilling stone, brick, concrete and most types of masonry.