Using thread dial and chart – Southbend South Bend EVS Toolroom SB1012 User Manual

Page 51

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For Machines Mfg. Since 7/09

EVS Toolroom Lathes

-49-

O P E R A T I O N

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.

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

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.

Figure 93. Any position on the dial for threading 4-72

TPI.

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

Any Position

TPI 2-54 Not Divisible By 4

Use any of the non-numbered lines on the thread
dial for threading the TPI shown in Figure 94.

TPI

Figure 94. Marks are selected on the dial for threading

2-54 TPI.

Non-
Numbered
Position

2,6,10,14,
18,22,26,
30,54

TPI

Odd Numbered TPI

Use any of the numbered lines on the thread dial
for threading the TPI shown in Figure 95.

Figure 95. Numbers are selected on the dial for

threading odd numbered TPI.

Numbered
Position
1,2,3,4

3,5,7,9,
11,13,15,
19,23,27

TPI

1

2

Fractional TPI

Use any opposing number pairs—2/4 or 1/3 on
the thread dial for

1

2

fractional TPI (Figure 96).

For example, to cut a 3

1

2

thread, select 1 on the

dial, then start threading, using 1 or 3 as your
reference points.

Figure 96. Opposing number group are selected on

dial for cutting

1

2

thread TPI.

Position
1,3 or 2,4

2½,3½,4½,
7½,11½,13½

TPI

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