Southbend SB1059F User Manual

For Machines Mfg. Since 3/11

EVS Toolroom Lathe w/DRO

-61-

The numbers on the thread dial are used with 
the thread dial chart to show when to engage the 
half nut during inch threading. The thread dial 
gear must be engaged with the leadscrew for this 
to work. Loosen the knurled knob on the thread 
dial, pivot the dial gear toward the leadscrew 
so that it properly meshes with the leadscrew 
threads, then re-tighten the knob, as shown 
Figure 80.

Find the TPI (threads per inch) that you want 
to cut in the left column of the thread dial chart 
(see Figure 81), 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.

4,8,12,16,20,24,
28,32,36,40,44,
48,56,60,72

Any Position

In.

Non-
Numbered 
Position
Numbered 
Position
1,2,3,4
Position
1,3 or 2,4
Position
1 Only

2,6,10,14,
18,22,26,
30,54
3,5,7,9,
11,13,15,
19,23,27
2½,3½,4½,
7½,11½,13½
2¼,2¾,
3¼,3¾

2

7

⁄

8

1

2

3

4

Same as  
Metric 
Threads

The thread dial is not used for metric 

threading, or diametral and modular pitches. 
You must leave the half nut engaged from the 
beginning until the turning is complete for these 
types of operations.

The following examples explain how to use the 
thread dial chart.

For threading a TPI that is divisible by four, use 
any line on the thread dial (see Figure 82).

4,8,12,16,20,24,
28,32,36,40,44,
48,56,60,72

Any Position