
O P E R A T I O N | For Machines Mfg. Since 3/11 |
Even TPI Not Divisible By 4
For threading a TPI that is even but not divisible by 4, use any of the
TPI
2,6,10,14, | Non- |
18,22,26, | Numbered |
30,54 | Position |
Figure 83. Marks are selected on the dial for threading
even TPI not divisible by 4.
Odd Numbered TPI
For odd numbered TPI, use any of the numbered lines on the thread dial (see Figure 84).
TPI |
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3,5,7,9, | Numbered |
11,13,15, | Position |
19,23,27 | 1,2,3,4 |
Figure 84. Numbers are selected on the dial for
threading odd numbered TPI.
1⁄2 Fractional TPI
Use any opposing number
1⁄4 or 3⁄4 Fractional TPI
For TPI that have a 1⁄4 or 3⁄4 fraction, use position 1 on the thread dial (see Figure 86).
TPI
2¼,2¾, | Position |
3¼,3¾ | 1 Only |
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Figure 86. Position for 1⁄4 or 3⁄4 fractional TPI.
27⁄8 TPI
The thread dial is not used for 2⁜7⁄8 or metric threading, or diametral and modular pitches (see Figure 87). The half nut must stay engaged with the leadscrew throughout the entire threading operation.
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| 27∕8 | Same as |
| Thread Dial |
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| Metric |
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| Not Used |
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| Threads |
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Figure 87. Half nut stays engaged for 27⁄8 TPI.
TPI
2½,3½,4½,
7½,11½,13½
Position 1,3 or 2,4