These were in a little booklet HAAS was giving out at Westec.

Cutting Speed (surface feet per minute)

SFM = .262 x DIA x RPM

Revolutions Per Minute

RPM = 3.82 x SFM/DIA

Feed Rate (inches per minute)

IPM = FPT x T (Number of Teeth) x RPM

Feed Per Revolution

FPR = IPM/RPM

Feed Per Tooth (in)

FPT = IPM/(RPM x Number of Teeth)

Metal Removal Rate

MRR = W (Width of cut) x D (Depth of cut) x F (Feed Rate in IPM)

Converting IPR to IPM

IPM = IPR x RPM

Converting IPM to IPR

IPR = IPM/RPM

Converting SFM to SMPM

SMPM = SFM x .3048

Converting IPR to MMPR

MMPR = IPR x 25.4

Tapping: Inch taps

.01299 x % of Full Thread

Tap Drill Size (Cut Threads) = Thread Dia - --------------------------

Number of TPI

Major Dia - Drilled Dia.

% of Full Thread (Cut taps) = Number of TPI x ----------------------

.01299

IPM (Mill Tapping Feed Rate) = RPM/TPI

IPR (Lathe Threading) = 1/TPI

.0068 x % of Full Thread

Form Tap Drill Size = Tap Dia - --------------------------

Number of TPI

(65% of Full Thread) .442

Form Tap Drill Size = Tap Dia - ---------------------

Number of TPI

Metric Taps:

% of Full Thread x mm Pitch

Tap Drill Size (metric) = Thread Dia (mm) -

-----------------------------

76.98

76.98

% of Full Thread (metric) = ----------- x [Thread Dia (mm)- Drilled Hole

Dia (mm)

mm Pitch

SMPM = RPM x Metric Pitch

(65% Form Thread)

Form Tap Drill Size (metric) = Tap Dia. - (.75 x Pitch (mm) x .65)

Tap Drill Size for Approximate 75% Thread:

Major Dia. LESS Thread pitch = Tap Drill Size

Thread pitch = 1.0 inch divided by Threads Per Inch

Inch Example: 3/8 - 16

(1 divided by 16 = .0625)

.375 - .0625 = .3125 Tap Drill

Metric Example:

M10 -1.5 = 10 - 1.5 = M8.5 Tap Drill

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BottleBob