Threading Technology – Clamping Technology 520

421 Twist Drills STEEL VA Accessories 3 x D Tech. Info v c / f Product Finder 5 x D 6 x D 8 x D 2-3.5 x D 5.2 Typical chip forms Start-of-drilling chip This chip type is produced in the start of the drilling process, before the cutting corners are engaged. Chamfer chip This chip type is created in the production of the chamfer. Optimal drilling chip This chip type is created when the cutting data are chosen to perfection. Step-drill chip The length of this chip type can be controlled by means of dwell times in long-chipping material. Drill-through chip Note: There is need for increased space between workpiece and tool holder. Hooked up chips These chips are produced especially in long-chipping materials, or when cutting data are not optimally chosen. Single entangled chips are not such a big issue, but when the entanglement of the chips becomes permanent it will soon lead to chip clogging, and with it to drill breakage. Drill-through slug Note: There is need for increased space for chips and lid in drilling through! Ribbon chip / flow chip Note: When you observe this chip type, the drill already has serious damage on primary cutting edge and chisel edge! This means an end to tool life. 5.3 Tool clamping Collet holders type PGR Concentricity < 3 µm • Slender construction • Reduced vibrations Shrink-fit chucks Concentricity < 3 µm • Slender construction Hydraulic expansion chucks Concentricity < 3 µm • Reduced vibrations Tool holders for straight shanks with inclined clamping flat Concentricity < 15 µm • Economically efficient 5.4 Differences in tool clamping with lateral driving flat and inclined clamping flat Lateral driving flat Clamping of tools with lateral driving flat acc. DIN 6535 HB resp. DIN 1835 B.This type of clamping has no axial support and is therefore not suitable for drilling operations. 2° Inclined clamping flat Clamping of tools with inclined clamping flat acc. DIN 6535 HE resp. DIN 1835 E.