For Machines Mfg. Since 7/09 | O P E R A T I O N | EVS Toolroom Lathes |
Using Thread Dial and Chart
Find the TPI (threads per inch) that you want to cut in the left column (see Figure 92), 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 Position |
28,32,36,40,44, |
|
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, | Position |
3¼,3¾ | 1 Only |
27⁄8 | Same as |
| Metric |
| Threads |
Figure 92. Thread dial chart.
The thread dial is not used for metric threading or for diametral or modular gear turning. You must leave the half nut lever engaged from the beginning until the threads are complete for these types of operations.
The following examples explain how to use the thread dial chart.
TPI 4-72 Divisible By 4
Use any line (position) on the thread dial, shown in Figure 93, for threading TPI divisible by four.
TPI
4,8,12,16,20,24, Any Position 28,32,36,40,44, 48,56,60,72
Figure 93. Any position on the dial for threading 4-72
TPI.
TPI 2-54 Not Divisible By 4
Use any of the
TPI
2,6,10,14, | Non- |
18,22,26, | Numbered |
30,54 | Position |
Figure 94. Marks are selected on the dial for threading
2-54 TPI.
Odd Numbered TPI
Use any of the numbered lines on the thread dial for threading the TPI shown in Figure 95.
TPI
3,5,7,9, | Numbered |
11,13,15, | Position |
19,23,27 | 1,2,3,4 |
Figure 95. 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 |
