| N |
T |
W
|
6
7
8
9 |
2
2
2
2 |
4.3604
4.4069
4.4534
4.5000 |
10
11
12
13 |
2
3
3
3 |
4.5465
7.3138
7.3604
7.4069 |
14
15
16
17 |
3
3
3
4 |
7.4534
7.5000
7.5465
10.3138 |
18
19
20
21 |
4
4
4
4 |
10.3604
10.4069
10.4534
10.5000 |
22
23
24
25 |
4
5
5
5 |
10.5464
13.3168
13.3604
13.4069 |
26
27
28 |
5
5
5 |
13.4534
13.5000
13.5464 |
|
| N |
T |
W
|
29
30
31
32 |
6
6
6
6 |
16.3138
16.3604
16.4069
16.4534 |
33
34
35
36 |
6
6
7
7 |
16.5000
16.5465
19.3138
19.3604 |
37
38
39
40 |
7
7
7
7 |
19.4069
19.4534
19.5000
19.5465 |
41
42
43
44 |
8
8
8
8 |
22.3138
22.3604
22.4069
22.4534 |
45
46
47
48 |
8
9
9
9 |
22.5000
25.2671
25.3138
25.3604 |
49
50
|
9
9
|
25.4069
25.4534
|
|
The limitations
of span measurement are:
1) Span measurement cannot be applied
when a combination of helix angle and narrow face width prevent the
caliper from spanning a sufficient number of teeth.
2) Readings are influenced by errors
in base pitch, tooth profile, and lead.
Readings would be erroneous if attempted on a portion of profile,
which had been modified from true involute shape.
Inspection of Tooth Thickness by Means
of a Span Measurement. |