TOOL GEOMETRY Standard conical point Normal point to DIN 1412 Use For all the usual drilling work in steel non-ferrous metals and plastics. The point angles depend on

TOOL GEOMETRY Standard conical point Normal point to DIN 1412 Use For all the usual drilling work in steel non-ferrous metals and plastics. The point angles depend on the machinability of the materials. Advantages Powerful major cutting edges insensitive to shock and lateral forces. Easy surface grind can be achieved manually. Disadvantages Wide chisel edge requires high feed force. Split point according to DIN 1412 C Use For drill bits with very strong core for particularly tough and hard materials and for deep hole drill bits. Advantages Improved chip transport due to chip separation. Disadvantages Perfect regrinding possible by mechanical means only. Point-thinned chisel edge according to DIN 1412 A Use For all the usual drilling work with drill bits with a strong core for large bore sizes for drilling into solid material. Advantages Good centring for tapping due to shortening of the chisel edge to 1 10 of the bore size and reduction of the feed force. Disadvantages Additional grinding work. Point for grey cast iron according to DIN 1412 D Use For drilling holes in grey cast iron malleable cast iron and forgings. Advantages The cut corners are protected by extended major cutting edges insensitive to shock good heat dissipation - therefore improved tool life. Disadvantages Additional effort for regrinding work. Point-thinned chisel edge after corrected major cutting edge according to DIN 1412 B Use For drill bits for high-strength steels for manganese steels with over 10% Mn for hard spring steels and for enlarging holes. Advantages Insensitive to shock one-sided load and lateral forces. No digging into thin-walled workpieces. Disadvantages High feed force tendency to drift and run untrue. Additional effort for regrinding work. Centre point according to DIN 1412 E Use For drilling sheet metals and soft materials for blind holes with flat bottom. Advantages Good centring low burr formation during through-drilling precise drillholes in thin sheet metals and pipes no digging in. Disadvantages Perfect surface grinding possible by mechanical means only. 2 NORGAU Cutting tools