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