Advertisement
The proper drill speed for a given drill bit size is as on following table:
Material
Cast
Type
Steel
s.f.m.
Drill Dia.
40
Inch
1/16
2,445
1/8
1,220
3/16
815
1/4
610
5/16
490
3/8
405
7/16
350
1/2
305
5/8
245
3/4
205
7/8
174
1
153
1-1/8
136
1-1/4
122
Tool Steel
Cast Iron
SURFACE FEET PER MINUTE
s.f.m.
s.f.m.
60
80
REVOLUTIONS PER MINUTE
3,665
4,890
1,835
2,445
1,220
1,630
915
1,220
735
980
610
815
525
700
460
610
365
490
305
405
261
348
229
306
204
272
167
244
11
Mild Steel
Alum. &
Copper
s.f.m.
s.f.m.
100
200
6,110
12,225
3,055
6,110
2,035
4,075
1,530
3,055
1,220
2,445
1,020
2,035
870
1745
765
1,530
610
1,220
510
1,020
435
762
382
668
340
595
306
535
Advertisement
