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Technical Information

Table of Contents

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Cutting Speeds

Speed, Feed & Power

Please use the chart below as a guide only. Many variables contribute to the optimum parameters for each application. These variables include: particular material characteristics, cutter design, cutter sharpness, airline pressure and flow capacity and cutter lubrication.

All portable drilling tools have limited power and thrust. In most cases, holes over 1/2 inch diameter cannot be produced at machine tool rates. Feed rates and/or speeds are reduced. Consult your mdi sales representative for advice on particular applications.


For best results with your drilling system:

  1. Maintain lubricated air to the tool with pressure of 90 psig while the tool is running.
  2. Use high quality cutters.
  3. Replace cutters when point dulls – hole diameter generally increases, cycle times lengthen (except positive feed) and hole finish worsens.
  4. Whenever possible, provide lubricant mist to the drill point.
  5. Insure there is an adequate flow path for drill chips (swarf).
  6. Utilize fixtures that are secure and rigid.
  7. Assure that accessory items are sized correctly and working properly.
  8. Train operating personnel in the proper use of the tool.
  9. Please consult the machinery handbook for optimum cutting feeds and speeds.

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Material Function Drill Diameter
1/8 3/16 1/4 5/16 3/8 7/16 1/2
.125 .188 .250 .313 .375 .437 .500
Aluminum (300 SFM) Speed (RPM) 9000 6000 4600 3600 3000 2600 2300
Feed Rate (IPR)  .002  .003  .004  .004  .004  .004  .004
Power (HP)  .2  .3  .6 1 .0 1 .5 1 .8 2 .0
Mild Steel (90 SFM) Speed (RPM) 2700 1800 1300 1100 900 750 650
Feed Rate (IPR)  .005  .005  .005  .006  .006  .006  .006
Power (HP)  .2  .3  .6 1 .0 1 .5 1 .8 2 .0
High Strength Stainless Steel(30 SFM) Speed (RPM) 900 600 450 375 300 250 220
Feed Rate (IPR)  .001  .001  .001  .001  .001  .001  .001
Power (HP)  .2  .3  .6 1 .0 1 .5 1 .8 2 .0
Titanium/Inconel(20 SFM) Speed (RPM) 600 400 300 250 200 175 150
Feed Rate (IPR)  .002  .003  .003  .003  .004  .004  .005
Power (HP)  .2  .3  .6 1 .0 1 .5 1 .8 2 .0
Composites Graphite, kevlar, fiberglass, and other composite materials vary widely. Fiber, resin, processing method and type of cutting tool all affect the optimum drilling speed and feedrate.
Little power or thrust is normally required, but controlled feedrates at the proper speed is mandatory. Carbide or diamond cutting tools are required. Contact your material supplier or experiment with an NC Drilling Machine.
Stacks of Various Materials Use the lowest speed and feedrate of the materials in the stack. Peck feed drilling is best.

A. Peck Drilling permits higher drilling speeds.
B. Carbide cutting tools (when applicable) permit higher drilling speeds.
C. Oil hole cutting tools permit higher drilling speeds.

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Speed (RPM)

Technical Info from Airetool

Describes the number of revolutions of the spindle per unit of time.

Example: Revolutions per minute = RPM

Surface Speed (SFM)

Technical Info from Airetool

Describes the velocity (speed) of the outside of the drill bit.

Example: 30 surface feet per minute (30 SFM)

Feed Rate (IPR)

Technical Info from Airetool

Describes the distance the spindle travels during each revolution.

Example: 0.002 inches per revolution = .002 IPR

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Recommended Cutting Speeds for Tube Cutters and Tube Facers

The recommended cutting speeds in this chart are based on published speeds and feeds. A slower RPM may be necessary depending on tube material analysis and hardness. Proper lubrication must be used.

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Tube Material Tube O.D.
1/4" 3/8" 1/2" 5/8" 3/4" 7/8" 1" 1-1/4" 1-1/2" 2"
Aluminum (500 FPM) 7500 rpm 5000 rpm 3800 rpm 3000 rpm 2500 rpm 2200 rpm 1900 rpm 1500 rpm 1275 rpm 950 rpm
Brass (300 FPM) 4600 rpm 3050 rpm 2300 rpm 1825 rpm 1625 rpm 1300 rpm 1150 rpm 925 rpm 750 rpm 575 rpm
Copper (250 FPM) 3825 rpm 2550 rpm 1900 rpm 1525 rpm 1275 rpm 1100 rpm 950 rpm 750 rpm 625 rpm 500 rpm
Carbon Steel (FPM) 2150 rpm 1425 rpm 1075 rpm 850 rpm 700 rpm 625 rpm 525 rpm 425 rpm 350 rpm 275 rpm
Stainless Steel (65 FPM) 1000 rpm 660 rpm 500 rpm 400 rpm 330 rpm 285 rpm 250 rpm 200 rpm 165 rpm 125 rpm
Titanium (30 FPM) 450 rpm 300 rpm 230 rpm 185 rpm 155 rpm 130 rpm 115 rpm 95 rpm 75 rpm 60 rpm
Inconel (20 FPM) 305 rpm 205 rpm 155 rpm 125 rpm 100 rpm 90 rpm 75 rpm 60 rpm 50 rpm 40 rpm

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Special Tables

Airetool Boiler Cleaner Motor Air Consumption Chart

Proper air supply and lubrication are imperative for proper operation of the Airetool boiler tube cleaner motors. 90 psi should be maintained at motor during operation for best cleaning results. Motor requires 20 to 30 drops of oil per minute.


Boiler Cleaner Motor — Air Consumption C.F.M.

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Model Number Pressure
60 Lbs. 80 Lbs. 100 Lbs.
3500 176 196 255
3450 174 194 248
3400 174 194 248
3350 155 178 207
3318 137 159 203
3312 129 149 200
3300 129 149 200
3275 127 147 172
3262 95 109 132
3250 93 106 127
3225 86 95 115
3212 79 87 103
3187 65 72 90
3175 57 69 86
3150 51 60 74
X-65-A 20 23 27
X-63-A 18 21 23
31 21 23 26
26 21 27 30
29 21 27 30
27A 9 10 11
27 9 10 11
30A 9 10 11
30 9 10 11
24 8 9 10
4600 119 134 149
4481 119 134 149
4450 76 85 93
4400 61 66 74
4350 61 66 74
4325 58 64 72
4300 57 63 71
4250 55 61 69
4225 33 37 41
4200 33 37 41
X-66 22 25 29
X-65 20 23 27
X-63 18 21 23
X-61 12 14 16
X-64 10 11 12

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Unit Conversion Tables

Decimal Equivalents

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Fractional Inches Decimal Inches
1/64 0.016
9/64 0.141
17/64 0.266
25/64 0.391
33/64 0.516
41/64 0.641
49/64 0.766
57/64 0.891
1/32 0.031
5/32 0.156
9/32 0.281
13/32 0.406
17/32 0.531
21/32 0.656
25/32 0.781
29/32 0.906
3/64 0.047
11/64 0.172
19/64 0.297
27/64 0.422
35/64 0.547
43/64 0.672
51/64 0.797
59/64 0.922
1/16 0.063
3/16 0.188
5/16 0.313
7/16 0.438
9/16 0.563
11/16 0.688
13/16 0.813
15/16 0.938
5/64 0.078
13/64 0.203
21/64 0.328
29/64 0.453
37/64 0.578
45/64 0.703
53/64 0.828
61/64 0.853
3/32 0.094
7/32 0.219
11/32 0.344
15/32 0.469
19/32 0.594
23/32 0.719
27/32 0.844
31/32 0.969
7/64 0.109
15/64 0.234
23/64 0.359
31/64 0.484
39/64 0.609
47/64 0.734
55/64 0.859
63/64 0.984
1/8 0.125
1/4 0.250
3/8 0.375
1/2 0.500
5/8 0.625
3/4 0.750
7/8 0.875
1 1.000

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Tube Sizes — Birmingham Wire Gauges

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OD of Tube (in.) Birmingham Wire Gauge
00-.380 0-.340 1-.300 2-.284 3-.259 4-.238 5-.220 6-.203 7-.180 8-.165 9-.148 10-.134 11-.120
1/4                          
3/8                          
5/8                          
3/4                       0.482 0.510
7/8                       0.607 0.635
1                   0.670 0.704 0.732 0.760
1-1/4                   0.920 0.954 0.982 1.010
1-1/2                   1.170 1.204 1.232 1.260
1-3/4             1.310 1.344 1.390 1.420 1.454 1.482 1.510
2           1.524 1.560 1.594 1.640 1.670 1.704 1.732 1.760
2-1/4 1.490 1.570 1.650 1.682 1.732 1.774 1.810 1.844 1.890 1.920 1.954 1.982 2.010
2-1/2 1.740 1.820 1.900 1.932 1.982 2.024 2.050 2.094 2.140 2.170 2.204 2.232 2.260
2-3/4 1.990 2.070 2.150 2.182 2.232 2.274 2.310 2.344 2.390 2.420 2.454 2.842 2.510
3 2.240 2.320 2.400 2.432 2.482 2.524 2.560 2.594 2.640 2.570 2.704 2.732 2.760
3-1/4 2.490 2.570 2.650 2.682 2.732 2.774 2.810 2.844 2.890 2.920 2.854 2.982 3.010
3-1/2 2.740 2.820 2.900 2.932 2.982 3.024 3.060 3.094 3.140 3.170 3.204 3.232 3.260
3-3/4 2.990 3.070 3.150 3.182 3.232 3.274 3.310 3.344 3.390 3.420 3.454 3.482 3/510
4 3.240 3.320 3.400 3.432 3.482 3.524 3.560 3.594 3.640 3.670 3.704 3.732 3.760
4-1/4 3.490 3.570 3.650 3.682 3.732 3.774 3.810 3.844 3.890 3.920 3.954 3.982 4.010
4-1/2 3.740 3.820 3.900 3.932 3.982 4.024 4.060 4.094 4.140 4.170 4.204 2.232 4.260
4-3/4 3.990 4.070 4.150 4.182 4.232 4.274 4.310 4.344 4.390 4.420 4.454 4.482 4.510
5 4.240 4.320 4.400 4.432 4.482 4.524 4.560 4.594 4.460 4.670 4.704 4.732 4.760
5-1/4 4.490 4.570 4.650 4.682 4.732 4.774 4.810 4.844 4.890 4.920 4.954 4.982 5.010

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OD of Tube (in.) Birmingham Wire Gauge
12-.109 13-.095 14-.083 15-.072 16-.065 17-.058 18-.049 19-.042 20-.035 21-.032 22-.028 23-.025 24-.022
1/4             0.152 0.166 0.180 0.186 0.194 0.200 0.206
3/8     0.209 0.231 0.245 0.259 0.277 0.291 0.305 0.311 0.319 0.325 0.331
1/2   0.310 0.334 0.356 0.370 0.384 0.402 0.416 0.430 0.436 0.444 0.450 0.456
5/8 0.407 0.435 0.459 0.481 0.495 0.509 0.527 0.541 0.555 0.561 0.569 0.575 0.581
3/4 0.532 0.560 0.584 0.606 0.620 0.634 0.652 0.666 0.680 0.686 0.694 0.700 0.706
7/8 0.657 0.685 0.709 0.731 0.745 0.759 0.777 0.791 0.805 0.811 0.819 0.825 0.831
1 0.782 0.810 0.834 0.856 0.870 0.884 0.902 0.916 0.930 0.936 0.944 0.950 0.956
1-1/4 1.032 1.060 1.084 1.106 1.120 1.134 1.152 1.166 1.180 1.186 1.194 1.200 1.206
1-1/2 1.282 1.310 1.334 1.356 1.370 1.384 1.402 1.416 1.430 1.436 1.444 1.450 1.456
1-3/4 1.532 1.560 1.584 1.606 1.620 1.634 1.652 1.666 1.680 1.686 1.694 1.700 1.706
2 1.782 1.810 1.834 1.856 1.870 1.884 1.902 1.916 1.930 1.935 1.944 1.950 1.956
2-1/4 2.032 2.060 2.084 2.106 2.120 2.134 2.151            
2-1/2 2.282 2.310 2.334 2.356 2.370 2.384 2.402            
2-3/4 2.532 2.560 2.584 2.606 2.620 2.634 2.652            
3 2.782 2.810 2.834 2.856 2.870 2.884 2.902            
3-1/4 3.032 3.060 3.084 3.105 3.120 3.134 3.151            
3-1/2 3.282 3.310 3.334 3.356 3.370 3.384 3.401            
3-3/4 3.532 3.560 3.584 3.606 3.620 3.634 3.652            
4 3.782 3.810 3.834 3.856 3.870 3.884 3.902            
4-1/4 4.032 4.060 4.084 4.106 4.120 4.134 4.152            
4-1/2 4.282 4.310 4.344 4.356 4.370 4.384 4.402            
4-3/4 4.532 4.560 4.584 4.606 4.620 4.634 4.652            
5 4.782 4.810 4.834 4.856 4.870 4.884 4.902            
5-1/4 5.032 5.060 5.084 5.106 5.120 5.134 5.152            

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Nominal Pipe Size (in.) Outside Diameter (in.) Schedule Number
Nominal Wall Thickness Inches / Nominal Inside Diameter Inches (ID)
40 ID 80 ID 120 ID 160 ID
1/8 0.405 0.068 0.269 0.095 0.215        
1/4 0.540 0.088 0.364 0.119 0.302        
3/8 0.675 0.091 0.493 0.126 0.423        
1/2 0.840 0.109 0.622 0.147 0.546     0.187 0.466
3/4 1.050 0.113 0.824 0.154 0.742     0.218 0.614
1 1.315 0.133 1.049 0.179 0.957     0.250 0.815
1-1/4 1.660 0.140 1.380 0.191 1.278     0.250 1.160
1-1/2 1.900 0.145 1.610 0.200 1.500     0.281 1.338
2 2.375 0.154 2.067 0.218 1.939     0.343 1.689
2-1/2 2.875 0.203 2.469 0.276 2.323     0.375 2.125
3 3.500 0.216 3.068 0.300 2.900     0.437 2.626
3-1/2 4.000 0.226 3.548 0.318 3.364        
4 4.500 0.237 4.026 0.337 3.826 0.437 3.626 0.531 3.438
5 5.563 0.258 5.047 0.375 4.813 0.500 4.563 0.625 4.313
6 6.625 0.280 6.065 0.432 5.761 0.562 5.501 0.718 5.189
8 8.625 0.322 7.981 0.500 7.625 0.718 7.189 0.906 6.813
10 10.750 0.365 10.020 0.593 9.564 0.843 9.064 1.125 8.500
12 12.750 0.406 11.938 0.687 11.378 1.000 10.750 1.312 10.126

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Thread Designations

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Size NC NF
in. mm
10 -32 4.8   10-32 UNF
1/4 6.4 1/4-20 UNC 1/4-28 UNF
5/16 7.9 5/16-18 UNC 5/16-24 UNF
3/8 9.5 3/8-16 UNC 3/8-24 UNF
7/16 11.1 7/16-14 UNC 7/16-20 UNF
1/2 12.7 1/2-13 UNC 1/2-20 UNF
9/16 14.3 9/16-12 UNC 9/16-18 UNF
5/8 15.9 5/8-11 UNC 5/8-18 UNF
3/4 19.1 3/4-10 UNC 3/4-16 UNF
7/8 22.2 7/8-9 UNC 7/8-14 UNF
1 25.4 1-8 UNC 1-14 UNS
1-1/8 28.6 1-1/8-7 UNC 1-1/8-12 UNF
1-3/8 34.9 1-3/8-16 UNC 1-3/8-12 UNF

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Metric Table Conversions

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Fractional Inch Decimal Inch Millimeter
1/64 0.016 0.40
1/32 0.031 0.79
3/64 0.047 1.19
1/16 0.063 1.59
5/64 0.078 1.98
3/32 0.094 2.38
7/64 0.109 2.78
1/8 0.125 3.18
9/64 0.141 3.57
5/32 0.156 3.97
11/64 0.172 4.36
3/16 0.188 4.76
13/64 0.203 5.16
7/32 0.219 5.56
15/64 0.234 5.95
1/4 0.250 6.35
17/64 0.266 6.75
9/32 0.282 7.14
19/64 0.297 7.54
5/16 0.313 7.94
21/64 0.328 8.33
11/32 0.344 8.73
23/64 0.359 9.13
3/8 0.375 9.53
25/64 0.391 9.92
13/32 0.406 10.32
27/64 0.422 10.72
7/16 0.438 11.11
29/64 0.453 11.51
15/32 0.469 11.10
31/64 0.484 12.30
1/2 0.500 12.70
33/64 0.516 13.10
17/32 0.531 13.50
35/64 0.547 13.89
9/16 0.563 14.29
37/64 0.578 14.68
19/32 0.594 15.08
39/64 0.609 15.48
5/8 0.625 15.88
41/64 0.641 16.27
21/32 0.656 16.67
43/64 0.672 17.07
11/16 0.688 17.46
45/64 0.703 17.86
23/32 0.719 18.26
47/64 0.734 18.65
3/4 0.750 19.05
49/64 0.766 19.45
25/32 0.781 19.84
51/64 0.797 20.24
13/16 0.813 20.64
53/64 0.828 21.03
27/32 0.844 21.43
55/64 0.860 21.83
7/8 0.875 22.23
57/64 0.891 22.62
29/32 0.906 23.02
59/64 0.922 23.42
61/64 0.953 24.21
31/32 0.969 24.61
63/64 0.984 25.00
1 1.000 25.40
2 2.000 50.80
3 3.000 76.20

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