The electric hammer drill bits are machined from chrome steel fitted with carbide insert brazed at a very high temperature to withstand severe heating when drilling hard materials. L-shaped flute profile improves dust discharge. Sand blasted surface. Other industrial surface finish available. For drilling in granite, concrete, stone, masonry, tiles and marble. ?4.0-30.0mm, Total length: 110-1000mm Fits hammer drills with SDS-Plus chucking and 2-slot chucking system. It can be used with Electric Hammer of BOSCH Co., AEG. Co., BLACK & DECKER Co., HILTI Co., PHILLIPS Co., HITACHI Co., and MAKITA Co., The shank is round with dual-arc and dual-key way.