254
PROGRAMMING EXAMPLES
96-8000
June 1999
FORMULAS
TAPPING -
STANDARD thread formula:
Revolutions per minute (RPM) divided by threads per inch (TPI) = Feed rate in inches per minute
RPM/TPI = F
METRIC thread formula:
Pitch (P) multiplied by .03937 = ____ multiplied by RPM = Feed rate in inches per minute
(P x .03937) x RPM = F
SPEED AND FEEDS -
S.F.M. (Surface Feet per Minute):
.262 multiplied by the cutter diameter multiplied by the RPM = SFM
.262 x Cutter Diameter x RPM = SFM
R.P.M. (Revolutions Per Minute):
3.82 multiplied by the recommended SFM divided by the cutter diameter = RPM
(3.82 x SFM) / Cutter Diameter = RPM
I.P.M. (Inch Per Minute):
Feed per tooth multiplied by the number of cutter teeth multiplied by the RPM = Feed rate in inches
per minute.
(Feed/tooth x n) x RPM = IPM or F
CUBIC INCH PER MINUTE: MATERIAL REMOVAL RATE
Effective diameter of cut multiplied by the depth of cut multiplied by the inch per minute feed rate =
cubic inch per minute.
(E Diameter x d) x IPM = CIPM