Drill bit shank The name comes from the German "Stecken – Drehen – Sichern" (Insert – Twist – Secure). In German-speaking countries the back-formation "Spannen durch System" (Clamping System) is used, though Bosch uses "Special Direct System" for international purposes. The triangle shank is almost always made by machining three flats on round bar stock. It is intended as a minor modification of a straight shank, still allowing it to be held in a 3-jaw drill chuck, but allowing higher torque transmission and limited slipping. The Morse taper twist drill bits pictured right are used in metalworking. The full range of tapers is
Down-the-hole drill the blast hole industry with many quarries embracing it with open arms. Eventually the larger DTH systems then found their way into other applications, such as water well drilling and construction work. It still offers the same benefits to the operator that it initially brought to the quarry industry but it is now being used in many different applications such as gold exploration, ground consolidation, geo-thermal drilling, shallow oil and gas well, directional and piling. The advent of tungsten carbide for the drill bits (the first bits were all-steel) and the development of the button drill bit coupled with the