Sharp 16 Series Manual page 19

2. Thread dial indicator for Metric leadscrew cutting metric threads.
There are two dials, 2&7 division and 3&5 division for Metric leadscrew
while using Metric thread dial indicator. Use 3&5 division dial for cutting
pitches 1.25, 2.5, 5.0, 2.25, 4.5; for the rest threads use 2&7 division dial.
Example 1 : For cutting pitches 0.5, 0.75, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, use the
14T worm gear and the 2&7 division dial. The dial numbers at which the
leadscrew nuts may be engaged are 7, that is, every division can be engaged
by leadscrew nuts.
Example 2 : For cutting pitches 1.75, 3.5, 7.0 also use the same 14T worm
gear and the 2&7 division dial. But the dial numbers at which the leadscrew
nuts may be engaged on 2; number 1 and 2.
Gear teeth
11T 2.75
13T 3.25
1.75
7
0.5
14T
1
2
4
1.25
15T 5
2.25
18T 6.75
Pitch Dial division
5.5
6.5
3.5
0.75
1.5
3
6
2.5
4.5
18
Half nuts engaged number
2
2
2
7
3
5
2
1
1
1,2
1,2,3,4,5,6,7
1,2,3
1,2,3
1,2