Thread Dial Chart
Find the TPI (threads per inch) that you want to cut in the left column of the thread dial chart (see Figure 82), then reference the dial number to the right of it. The dial numbers indicate when to engage the half nut for a specific thread pitch. The thread dial chart can also be found on the front of the thread dial housing.
In. |
|
|
| 2 | 3 |
| 1 | 4 |
|
| |
4,8,12,16,20,24, | Any |
|
28,32,36,40,44, | Position | |
48,56,60,72 |
|
|
2,6,10,14, | Non- |
|
18,22,26, | Numbered | |
30,54 | Position | |
3,5,7,9, | Numbered | |
11,13,15, | Position | |
19,23,27 | 1,2,3,4 | |
2½,3½,4½, | Position | |
7½,11½,13½ | 1,3 or 2,4 | |
2¼,2¾,3¼,3¾ | Position | |
| 1 Only | |
27⁄8 | Same as | |
| Metric |
|
| Threads | |
Figure 82. Thread dial chart.
Note: The thread dial is not used for metric threading, or diametral and modular pitches. You must leave the half nut engaged from the begin- ning until the turning is complete for these types of operations.
The following examples explain how to use the thread dial chart.
TPI Divisible By 4
For threading a TPi that is divisible by four, use any line on the thread dial (see Figure 83).
TPI
4,8,12,16,20,24, Any Position 28,32,36,40,44, 48,56,60,72
Figure 83. Any position on the dial for threading
TPI divisible by 4.
Model G0740 (Mfg. Since 11/12)
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 84. 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 85).
TPI
3,5,7,9, | Numbered |
11,13,15, | Position |
19,23,27 | 1,2,3,4 |
|
|
Figure 85. Numbers are selected on the dial for
threading odd numbered TPI.
1⁄2 Fractional TPI
Use any opposing number
TPI
2½,3½,4½, | Position |
7½,11½,13½ | 1,3 or 2,4 |
|
|
