TB 9-5210-205-50
MAXIMUM PERMITTED DEVIATIONS OF THE LENGTH AT ANY POINT AND PARALLELISM
TOLERANCES FOR METRIC GAGE BLOCKS
Nominal Length
Grade 0
Grade AS-1
Range, ln (mm)
Former
Former
Grade AS-2
Grade 2 (m)
Grade 3 (m)
(m)
te2
tv3
te2
tv3
te2
tv3
ln ≤ 0.5
0.14
0.10
0.30
0.16
0.60
0.30
0.5 < ln ≤ 10
0.12
0.10
0.20
0.16
0.45
0.30
10 < ln ≤ 25
0.14
0.10
0.30
0.16
0.60
0.30
25 < ln ≤ 50
0.20
0.10
0.40
0.18
0.80
0.30
50 < ln ≤ 75
0.25
0.12
0.50
0.18
1.00
0.35
75 < ln ≤ 100
0.30
0.12
0.60
0.20
1.20
0.35
100 < ln ≤ 150
0.40
0.14
0.80
0.20
1.60
0.40
150 < ln ≤ 200
0.50
0.16
1.00
0.25
2.00
0.40
200 < ln ≤ 250
0.60
0.16
1.20
0.25
2.40
0.45
250 < ln ≤ 300
0.70
0.18
1.40
0.25
2.80
0.50
300 < ln ≤ 400
0.90
0.20
1.80
0.30
3.60
0.50
400 < ln ≤ 500
1.10
0.25
2.20
0.35
4.40
0.60
MAXIMUM PERMITTED DEVIATIONS OF THE LENGTH AT ANY POINT AND PARALLELISM
TOLERANCES FOR INCH GAGE BLOCKS
Nominal Length
Grade 0
Grade AS-1
Range, ln (in)
Former
Former
Grade AS-2
Grade 2 (in.)
Grade 3 (in.)
(in.)
tv3
te2
tv3
te2
tv3
te2
ln ≤ 0.05
6
4
12
6
24
12
0.05 < ln ≤ 0.4
5
4
8
6
18
12
0.45 < ln ≤ 1
6
4
12
6
24
12
1 < ln ≤ 2
8
4
16
6
32
12
2 < ln ≤ 3
10
4
20
6
40
14
3 < ln ≤ 4
12
5
24
8
48
14
4 < ln ≤ 5
16
5
32
8
64
16
5 < ln ≤ 6
16
5
32
8
64
16
6 < ln ≤ 7
20
6
40
10
80
16
7 < ln ≤ 8
20
6
40
10
80
16
8 < ln ≤ 10
24
6
48
10
104
18
10 < ln ≤ 12
28
7
56
10
112
20
12 < ln ≤ 16
36
8
72
12
144
20
16 < ln ≤ 20
44
10
88
14
176
24
Individual blocks which deviate more than twice the length, flatness or parallelism tolerances for new blocks or which have
1
lost their wringing qualities should be replaced. Blocks that have only undergone a length change do not need replacement if
corrections from a calibration report are applied in usage. When recalibration indicates that 25 percent or more of the blocks
in a set should be replaced, the entire set normally should be assigned to lower accuracy work.
2 te = Limit deviations of length at any point from nominal length.
3 tv = Tolerances for parallelism.
3