Surface Feet Conversion Chart
Surface Feet per Minute (SFM) is the unit of velocity used in machining to identify the machinability ratings of a specific material.
The following chart reveals CERATIZIT Sacramento (formerly PROMAX Tools) recommendation regarding how many feet your end mill should travel, per minute, in the material that you are cutting.
Once the SMF is determined, this information can be used to help decipher the proper starting point for the feeds and speeds needed while using PROMAX Premium and DESIGN-RITE XL end mills on your particular job. Whether you are using our roughing end mills or finishing end mills, the following information is critical in determining where you should begin. Please note that the results are a starting point and may need to be adjusted in order to gain optimum results.
Should you have difficulties determining the proper SMF for your job, please contact the very knowledgeable CERATIZIT Sacramento Technical Department at 800-878-0502. We will be happy to assist you with your calculations.
Surface Feet Conversion Chart
Surface Feet Per Minute (SFM) to Revolutions Per Minute (RPM)
RPM
Cutter Diameter
| SFM | 1/8" | 1/4" | 3/8" | 1/2" | 5/8" | 3/4" | 7/8" | 1" |
|---|---|---|---|---|---|---|---|---|
| 10 | 305 | 153 | 102 | 76 | 61 | 51 | 44 | 38 |
| 15 | 458 | 229 | 153 | 115 | 92 | 76 | 65 | 57 |
| 20 | 611 | 305 | 204 | 153 | 122 | 102 | 87 | 76 |
| 25 | 763 | 382 | 254 | 191 | 153 | 127 | 109 | 95 |
| 30 | 916 | 458 | 305 | 229 | 183 | 153 | 131 | 115 |
| 35 | 1,069 | 534 | 356 | 267 | 214 | 178 | 153 | 134 |
| 40 | 1,221 | 611 | 407 | 305 | 244 | 204 | 174 | 153 |
| 45 | 1,374 | 687 | 458 | 344 | 275 | 229 | 196 | 172 |
| 50 | 1,527 | 763 | 509 | 382 | 305 | 254 | 218 | 191 |
| 60 | 1,832 | 916 | 611 | 458 | 366 | 305 | 262 | 229 |
| 70 | 2,137 | 1,069 | 712 | 534 | 427 | 356 | 305 | 267 |
| 80 | 2,443 | 1,221 | 814 | 611 | 489 | 407 | 349 | 305 |
| 90 | 2,748 | 1,374 | 916 | 687 | 550 | 458 | 393 | 344 |
| 100 | 3,053 | 1,527 | 1,018 | 763 | 611 | 509 | 436 | 382 |
| 150 | 4,580 | 2,290 | 1,527 | 1,145 | 916 | 763 | 654 | 573 |
| 200 | 6,107 | 3,053 | 2,036 | 1,527 | 1,221 | 1,018 | 872 | 763 |
| 250 | 7,634 | 3,817 | 2,545 | 1,908 | 1,527 | 1,272 | 1,091 | 954 |
| 300 | 9,160 | 4,580 | 3,053 | 2,290 | 1,832 | 1,527 | 1,309 | 1,145 |
| 350 | 10,687 | 5,344 | 3,562 | 2,672 | 2,137 | 1,781 | 1,527 | 1,336 |
| 400 | 9,160 | 4,580 | 3,053 | 2,290 | 1,832 | 1,527 | 1,309 | 1,145 |
| 450 | 13,740 | 6,870 | 4,580 | 3,435 | 2,748 | 2,290 | 1,963 | 1,718 |
| 500 | 15,267 | 7,634 | 5,089 | 3,817 | 3,053 | 2,545 | 2,181 | 1,908 |
| 600 | 18,321 | 9,160 | 6,107 | 4,580 | 3,664 | 3,053 | 2,617 | 2,290 |
| 800 | 24,427 | 12,214 | 8,142 | 6,107 | 4,885 | 4,071 | 3,490 | 3,053 |
| 900 | 27,481 | 13,740 | 9,160 | 6,870 | 5,496 | 4,580 | 3,926 | 3,453 |
| 1000 | 30,534 | 15,267 | 10,178 | 7,634 | 6,107 | 5,089 | 4,362 | 3,817 |
| 1100 | 33,588 | 16,794 | 11,196 | 8,397 | 6,718 | 5,598 | 4,798 | 4,198 |
| 1200 | 36,641 | 18,321 | 12,214 | 9,160 | 7,328 | 6,107 | 5,234 | 4,580 |
| 1300 | 39,695 | 19,847 | 13,232 | 9,924 | 7,939 | 6,616 | 5,671 | 4,962 |
| 1400 | 42,748 | 21,374 | 14,249 | 10,687 | 8,550 | 7,125 | 6,107 | 5,344 |
| 1500 | 45,802 | 22,901 | 15,267 | 11,450 | 9,160 | 7,634 | 6,543 | 5,725 |
| 1600 | 48,855 | 24,427 | 16,285 | 12,214 | 9,771 | 8,142 | 6,979 | 6,107 |
| 1700 | 51,908 | 25,954 | 17,303 | 12,977 | 10,382 | 8,651 | 7,415 | 6,489 |
| 1800 | 54,962 | 27,481 | 18,321 | 13,740 | 10,992 | 9,160 | 7,852 | 6,870 |
| 1900 | 58,015 | 29,088 | 19,338 | 14,504 | 11,603 | 9,669 | 8,288 | 7,252 |
| 2000 | 61,069 | 30,534 | 20,356 | 15,267 | 12,214 | 10,178 | 8,724 | 7,634 |
Formulas:
SFM = RPM x Diameter x .262
RPM = (SFM x 3.82) / Diameter