to use the thread chart, find the tpi that you want
to cut and reference the "scale" number(s) next to
it. the scale number(s) indicate when to engage
the half nut when cutting that tpi.
for example: if you are cutting 18 tpi threads,
the chart shows "1 or 3" next to the 18 (see the
shaded boxes in figure 64).
indicator scale
tpi
scale
4
1 - 4
4
⁄
1
1
2
5
1
5
⁄
1
1
2
6
1 or 3
6
⁄
1
1
2
7
1
8
1 - 8
9
1
9
⁄
1
1
2
10
1 or 3
11
1
11
⁄
1
1
2
12
1 - 4
13
1
14
1 or 3
16
1 - 8
18
1 or 3
19
1
20
1 - 4
22
1 or 3
23
1
figure 64. thread dial chart.
Model g9036 Mfg. 7/08+
tpi
scale
24
1 - 8
26
1 or 3
28
1 - 4
32
1 - 8
36
1 - 4
38
1 or 3
40
1 - 8
44
1 - 4
46
1 or 3
48
1 - 8
52
1 - 4
56
1 - 8
64
1 - 8
72
1 - 8
76
1 - 4
80
1 - 8
88
1 - 8
92
1 - 4
96
1 - 8
104
1 - 8
112
1 - 8
A "1 or 3" means that you must engage the half
nut when the 1 or 3 scale mark lines up with the
fixed indicator, shown in figure 65.
figure 65. thread dial close-up.
A "1" means that you can only engage the half nut
when the 1 lines up with the fixed indicator.
A "1-8" means that you can engage the half nut
when the fixed indicator lines up with any number
on the dial.
to maintain accuracy and consistency, engage
the half nut on the same number mark on each
pass. Failure to start on the same number each
time may lead to cutting off the thread made in
the previous pass.
Fixed indicator
-39-