Professional Hammer Drill Bit are made for professional quality only to drill various concrete, bricks, masonry materials, etc. Super quality carbide is taken for most durable drilling performance. Auto-copper soldering is under German tech. guaranteeing the best advantages in drilling. Automatic-copper-soldering guarantees best welding strength and copper wrapping carbide for prolonged drilling life. Over 1200centidegree soldering temperature guarantee the drill bit fitting different working environments