d1 K d2 60° 120° 120°60° 118° DIN-333 B Center drills WK For center drilling, B type HSS l1 l2 DIN 333 B P M K Material groups N S H Internal cooling - Quality of material HSS Coating - Point angle 60° Nakrój / Chamfer Norm DIN-333 B d1 d2 K l1 l2 min-max INDEX W1-021021 1,00 4,0 2,1 35 1,3~1,7 01001,255,02,6401,6~2,00125 6 1,60 6,3 3,3 45 2,0~2,6 0160 2,00 8,0 4,2 50 2,5~3,1 0200 2,50 10,0 5,3 55 3,1~3,8 0250 3,15 11,2 6,7 62 3,9~4,6 0315 4,00 14,0 8,5 69 5,0~5,9 0400 5,00 18,0 10,6 77 6,3~7,2 0500 6,30 20,0 13,2 80 8,0~8,9 0630 Feed [mm/rev] Vc (m/min) Ø2-Ø6 Ø6-Ø10 Ø10-Ø16 Rm<500 30-35 0,08-0,15 0,15-0,25 0,25-0,30 Rm<800 20-25 0,08-0,15 0,15-0,25 0,25-0,30 P Rm<1000 15-25 0,05-0,14 0,14-0,20 0,20-0,25 Rm<1400 - - - - M 6-10 0,04-0,12 0,12-0,18 0,18-0,22 K 15-20 0,08-0,15 0,15-0,20 0,20-0,25 N 30-80 0,08-0,15 0,15-0,20 0,20-0,25 B type center drills advantages B type center drill Removes burrs of center hole It is recommended to use type B center drills when poor quality of the workpieces surface Example of order 169 W1-021021-0100 Center drill DIN-333 B 60° 1,0 HSS