88 Materials HSS- Co HSS- TiN HSS-G HSS-R Steel (N/mm2 ) 900 Steel (N/mm2 ) < 1100 Steel (N/mm2 ) < 1300 Stainless steels Aluminium Brass Bronze Plastics Cast iron TECHNICAL DETAILS METAL DRILL BITS QUALITY FEATURES High-quality tools are crucial to process metals. The exact connection of components requires an accurately produced holes. Unsmooth or incorrectly produced holes with burrs may cause reworking and the quality is crucially impaired. As a consequence, it is paramount to use drill bits produced in compliance with the applicable DIN standards. The following DIN standards apply for helical drill bits with a cylinder shaft: DIN 338 Helical drill bits with cylinder shaft DIN 1897 Extra short helical drill bits with cylinder shaft DIN 340 Long helical drill bits with cylinder shaft DIN 1869 Extra long helical drill bits with cylinder shaft DIN 1414 Technical delivery conditions for helical drill bits made of high-speed steel (HSS) Excellent choice suitable for occassional use MANUFACTURING METHOD Helical grinding This process involves cutting the helix from a round rod. These bits are extremely precise and used for quality work. A cut bit is normally identifiable by its silver colour. Roller pressing More simple bits are manufactured using a (hot) roll- er-pressing process. A round metal bar is clamped by a mould, thus giving it a helical shape. These bits are perfect for rough work. Roller-pressed bits are often identifiable by their black colour