Powermatic 1200HD, Instruction Manual & Parts List

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TABLE 3: TAPPING AND THREADING FORMULA FOR CALCULATING
HORSEPOWER REQUIREMENTS
MATERIAL AND SPEED FACTORS CHART
MATERIAL FACTOR - M SPEED - S.F.M.
Aluminum 0.5 100
Bakelite 0.6 75
Brass 0.6 90
Bronze 0.6 50
Bronze Mang. 1 40
Copper 0.5 80
Alum. Die Cast 0.6 80
Fiber 0.5 75
Zinc Die Cast 0.6 80
Cast Iron 0.6 70
Malleable Iron 0.6 45
Magnesium 0.5 100
Steel Cast 1.4 35
Steel Fr. Mach. 1 50
Steel Chromium 1.7 30
Steel Alloy 1.7 25
Steel Stainless 1.7 20
REVOLUTIONS PER MINUTE CALCULATION
R.P.M. = 3.82 X S.F.M. + Dia.
PPV = Power Pitch Value
SFM = Surface Feet Per Minute
M = Material Factor
TD = Tool Dullness Factor
HP = Horsepower
RPM = Revolutions Per Minute
HP = PPV x SFM x M x TD
TAPPING AND THREADING FACTORS CHART
Threads per inch Power Pitch Value* PPV
32 0.002
27 0.0034
24 0.004
20 0.006
18 0.007
16 0.009
14 0.011
13 0.012
12 0.014
11-1/2 0.015
11 0.016
10 0.02
9 0.025
8 0.03
7 0.035
6 0.04
Multiply PPV by 2.2 for Double or Taper Pipe Threads
TD - Use (1.5 Factor) for Tool Dullness