标准公差数值 （GB/T 1800.3—1998）
基本尺寸/
mm
|
标 准 公 差 等 级
|
IT1
|
IT2
|
IT3
|
IT4
|
IT5
|
IT6
|
IT7
|
IT8
|
IT9
|
IT10
|
IT11
|
IT12
|
IT13
|
IT14
|
IT15
|
IT16
|
IT17
|
IT18
|
大于
|
至
|
μm
|
mm
|
—
|
3
|
0.8
|
1.2
|
2
|
3
|
4
|
6
|
10
|
14
|
25
|
40
|
60
|
0.1
|
0.14
|
0.25
|
0.4
|
0.6
|
1
|
1.4
|
3
|
6
|
1
|
1.5
|
2.5
|
4
|
5
|
8
|
12
|
18
|
30
|
48
|
75
|
0.12
|
0.18
|
0.3
|
0.48
|
0.75
|
1.2
|
1.8
|
6
|
10
|
1
|
1.5
|
2.5
|
4
|
6
|
9
|
15
|
22
|
36
|
58
|
90
|
0.15
|
0.22
|
0.36
|
0.58
|
0.9
|
1.5
|
2.2
|
10
|
18
|
1.2
|
2
|
3
|
5
|
8
|
11
|
18
|
27
|
43
|
70
|
110
|
0.18
|
0.27
|
0.43
|
0.7
|
1.1
|
1.8
|
2.7
|
18
|
30
|
1.5
|
2.5
|
4
|
6
|
9
|
13
|
21
|
33
|
52
|
84
|
130
|
0.21
|
0.33
|
0.52
|
0.84
|
1.3
|
2.1
|
3.3
|
30
|
50
|
1.5
|
2.5
|
4
|
7
|
11
|
16
|
25
|
39
|
62
|
100
|
160
|
0.25
|
0.39
|
0.62
|
1
|
1.6
|
2.5
|
3.9
|
50
|
80
|
2
|
3
|
5
|
8
|
13
|
19
|
30
|
46
|
74
|
120
|
190
|
0.3
|
0.46
|
0.74
|
1.2
|
1.9
|
3
|
4.6
|
80
|
120
|
2.5
|
4
|
6
|
10
|
15
|
22
|
35
|
54
|
87
|
140
|
220
|
0.35
|
0.54
|
0.87
|
1.4
|
2.2
|
3.5
|
5.4
|
120
|
180
|
3.5
|
5
|
8
|
12
|
18
|
25
|
40
|
63
|
100
|
160
|
250
|
0.4
|
0.63
|
1
|
1.6
|
2.5
|
4
|
6.3
|
180
|
250
|
4.5
|
7
|
10
|
14
|
20
|
29
|
46
|
72
|
115
|
185
|
290
|
0.46
|
0.72
|
1.15
|
1.85
|
2.9
|
4.6
|
7.2
|
250
|
315
|
6
|
8
|
12
|
16
|
23
|
32
|
52
|
81
|
130
|
210
|
320
|
0.52
|
0.81
|
1.3
|
2.1
|
3.2
|
5.2
|
8.1
|
315
|
400
|
7
|
9
|
13
|
18
|
25
|
36
|
57
|
89
|
140
|
230
|
360
|
0.57
|
0.89
|
1.4
|
2.3
|
3.6
|
5.7
|
8.9
|
400
|
500
|
8
|
10
|
15
|
20
|
27
|
40
|
63
|
97
|
155
|
250
|
400
|
0.63
|
0.97
|
1.55
|
2.5
|
4
|
6.3
|
9.7
|
500
|
630
|
9
|
11
|
16
|
22
|
32
|
44
|
70
|
110
|
175
|
280
|
440
|
0.7
|
1.1
|
1.75
|
2.8
|
4.4
|
7
|
11
|
630
|
800
|
10
|
13
|
18
|
25
|
36
|
50
|
80
|
125
|
200
|
320
|
500
|
0.8
|
1.25
|
2
|
3.2
|
5
|
8
|
12.5
|
800
|
1000
|
11
|
15
|
21
|
28
|
40
|
56
|
90
|
140
|
230
|
360
|
560
|
0.9
|
1.4
|
2.3
|
3.6
|
5.6
|
9
|
14
|
1000
|
1250
|
13
|
18
|
24
|
33
|
47
|
66
|
105
|
165
|
260
|
420
|
660
|
1.05
|
1.65
|
2.6
|
4.2
|
6.6
|
10.5
|
16.5
|
1250
|
1600
|
15
|
21
|
29
|
39
|
55
|
78
|
125
|
195
|
310
|
500
|
780
|
1.25
|
1.95
|
3.1
|
5
|
7.8
|
12.5
|
19.5
|
1600
|
2000
|
18
|
25
|
35
|
46
|
65
|
92
|
150
|
230
|
370
|
600
|
920
|
1.5
|
2.3
|
3.7
|
6
|
9.2
|
15
|
23
|
2000
|
2500
|
22
|
30
|
41
|
55
|
78
|
110
|
175
|
280
|
440
|
700
|
1100
|
1.75
|
2.8
|
4.4
|
7
|
11
|
17.5
|
28
|
2500
|
3150
|
26
|
36
|
50
|
68
|
96
|
135
|
210
|
330
|
540
|
860
|
1350
|
2.1
|
3.3
|
5.4
|
8.6
|
13.5
|
21
|
33
|
注：1．基本尺寸大于500mm的IT1至IT5的标准公差数值为试行的。
2．基本尺寸小于或等于1mm时，无IT14至IT18。
