| Material |
Hardness |
Speed (SFM) |
Feed (IPR) |
| 1/8" 3mm |
1/4" 6mm |
3/8" 10mm |
1/2" 13mm |
5/8" 16mm |
3/4" 19mm |
| Alloyed Steel 4340, 52100, 8620, 4104 |
<= 28 - 32 Rc |
190 - 225 |
.0026 |
.0043 |
.0072 |
.0090 |
.0099 |
.0109 |
| <= 42 Rc |
140 - 145 |
.0020 |
.0034 |
.0056 |
.0070 |
.0077 |
.0085 |
| Mold Steel P-20, H-13, 180, D2, A2, S-5 |
180 - 320 BnH |
190 - 225 |
.0029 |
.0048 |
.0080 |
.0100 |
.0110 |
.0121 |
| 220-250 BnH |
85 - 105 |
.0017 |
.0029 |
.0048 |
.0060 |
.0066 |
.0073 |
| 50+ Rc |
50 - 60 |
.0012 |
.0019 |
.0032 |
.0040 |
.0044 |
.0048 |
Iron Gray CI 30, G25 |
150 - 220 BnH |
190 - 450 |
.0058 |
.0096 |
.0160 |
.0200 |
.0220 |
.0242 |
| Iron Ductile |
220 - 250 BnH |
150 - 300 |
.0035 |
.0058 |
.0096 |
.0120 |
.0132 |
.0145 |
| Iron Nodular |
251 - 320 BnH |
165 - 250 |
.0023 |
.0038 |
.0064 |
.0080 |
.0088 |
.0097 |
| Stainless Steels Free 303, 420, 416 |
< 330 HB
<= 40 HRc |
200 - 260 |
.0023 |
.0038 |
.0064 |
.0080 |
.0088 |
.0097 |
| Stainless Steels Tough 316, 304, 15-5, 13-8, 17-4 |
330 - 450 BHN
36 - 48 HRc |
160 - 195 |
.0017 |
.0029 |
.0048 |
.0060 |
.0066 |
.0073 |
| Titanium Alloys Ti-6AI 4V, 6A16V |
110 - 450 HB
<= 48 HRc |
90 - 115 |
.0017 |
.0029 |
.0048 |
.0060 |
.0066 |
.0073 |
| Nickel Alloys 718, Inconel, Rene, Nimonic, Waspalloy |
140 - 475 HB
<= 48 HRc |
55 - 80 |
.0012 |
.0019 |
.0032 |
.0040 |
.0044 |
.0048 |
Higher speed and feed values should be favored for
software material; lower speed and feed values should be used for harder
materials. These recommendations should be considered only as a starting
point. Ultimate speeds and feeds will depend upon setup conditions and
chip formation.
The above recommendations are for drilling a
hole 2 x diameter deep. For other depths, multiply feed rate from above
as follows:
| Drilling Depth (N x diameter) |
1 |
2 |
3 |
4 |
5 |
| Multiplier |
1.2 |
1.0 |
0.9 |
0.75 |
0.65 |
