攻丝前钻孔用麻花钻直径 GB /T 20330 - 2006
-
用于普通螺纹（按GB/T 193-2003) 的麻花钻直径 —— 粗牙系列
螺纹
麻花钻
直径
mm
公称
直径
螺距
下列等级的小径 (mm)
5H
最大
6H
最大
7H
最大
5H、6H、7H
最小
1
0.25
0.785
/
/
0.729
0.75
1.1
0.25
0.885
/
/
0.829
0.85
1.2
0.25
0.985
/
/
0.929
0.95
1.4
0.3
1.142
1.16
/
1.075
1.1
1.6
0.35
1.301
1.321
/
1.221
1.25
1.8
0.35
1.501
1.521
/
1.421
1.45
2
0.4
1.657
1.679
/
1.567
1.6
2.2
0.45
1.813
1.838
/
1.713
1.75
2.5
0.45
2.113
2.138
/
2.013
2.05
3
0.5
2.571
2.599
2.639
2.459
2.5
3.5
0.6
2.975
3.01
3.05
2.85
2.9
4
0.7
3.382
3.422
3.466
3.242
3.3
4.5
0.75
3.838
3.878
3.924
3.688
3.7
5
0.8
4.294
4.334
4.384
4.134
4.2
6
1
5.107
5.153
5.217
4.917
5
7
1
6.107
6.153
6.217
5.917
6
8
1.25
6.859
6.912
6.982
6.647
6.8
9
1.25
7.859
7.912
7.982
7.647
7.8
10
1.5
8.612
8.676
8.751
8.376
8.5
11
1.5
9.612
9.676
9.751
9.376
9.5
12
1.75
10.371
10.441
10.531
10.106
10.2
14
2
12.135
12.21
12.31
11.835
12
16
2
14.135
14.21
14.31
13.835
14
18
2.5
15.649
15.744
15.854
15.294
15.5
20
2.5
17.649
17.744
17.854
17.294
17.5
22
2.5
19.649
19.744
19.854
19.294
19.5
24
3
21.152
21.252
21.382
20.752
21
27
3
24.152
24.252
24.382
23.752
24
30
3.5
26.661
26.771
26.921
26.211
26.5
33
3.5
29.661
29.771
29.921
29.211
29.5
36
4
32.145
32.27
32.42
31.67
32
39
4
35.145
35.27
35.42
34.67
35
42
4.5
37.659
37.779
37.979
37.129
37.5
45
4.5
40.659
40.779
40.979
40.129
40.5
48
5
43.147
43.297
43.487
42.587
43
52
5
47.147
47.297
47.487
46.587
47
56
5.5
50.646
50.796
50.996
50.046
50.5
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用于普通螺纹（按GB/T 193-2003) 的麻花钻直径 —— 细牙系列
螺纹
麻花钻
直径
mm
公称
直径
螺距
下列等级的小径 (mm)
5H
最大
6H
最大
7H
最大
5H、6H、7H
最小
2.5
0.35
2.201
2.221
/
2.121
2.15
3
0.35
2.701
2.721
/
2.621
2.65
3.5
0.35
3.201
3.221
/
3.121
3.15
4
0.5
3.571
3.599
3.639
3.459
3.5
4.5
0.5
4.071
4.099
4.139
3.959
4
5
0.5
4.571
4.599
4.639
4.459
4.5
5.5
0.5
5.071
5.099
5.139
4.959
5
6
0.75
5.338
5.378
5.424
5.188
5.2
7
0.75
6.338
6.378
6.424
6.188
6.2
8
0.75
7.338
7.378
7.424
7.188
7.2
9
0.75
8.338
8.378
8.424
8.188
8.2
10
0.75
9.338
9.378
9.424
9.188
9.2
11
0.75
10.338
10.378
10.424
10.188
10.2
8
1
7.107
7.153
7.217
6.917
7
9
1
8.107
8.153
8.217
7.917
8
10
1
9.107
9.153
9.217
8.917
9
11
1
10.107
10.153
10.217
9.917
10
12
1
11.107
11.153
11.217
10.917
11
14
1
13.107
13.153
13.217
12.917
13
15
1
14.107
14.153
14.217
13.917
14
16
1
15.107
15.153
15.217
14.917
15
17
1
16.107
16.153
16.217
15.917
16
18
1
17.107
17.153
17.217
16.917
17
20
1
19.107
19.153
19.217
18.917
19
22
1
21.107
21.153
21.217
20.917
21
24
1
23.107
23.153
23.217
22.917
23
25
1
24.107
24.153
24.217
23.917
24
27
1
26.107
26.153
26.217
25.917
26
28
1
27.107
27.153
27.217
26.917
27
30
1
29.107
29.153
29.217
28.917
29
10
1.25
8.859
8.912
8.982
8.647
8.8
12
1.25
10.859
10.912
10.982
10.647
10.8
14
1.25
12.859
12.912
12.982
12.647
12.8
12
1.5
10.612
10.676
10.751
10.376
10.5
14
1.5
12.612
12.676
12.751
12.376
12.5
15
1.5
13.612
13.676
13.751
13.376
13.5
16
1.5
14.612
14.676
14.751
14.376
14.5
17
1.5
15.612
15.676
15.751
15.376
15.5
18
1.5
16.612
16.676
16.751
16.376
16.5
20
1.5
18.612
18.676
18.751
18.376
18.5
22
1.5
20.612
20.676
20.751
20.376
20.5
24
1.5
22.612
22.676
22.751
22.376
22.5
25
1.5
23.612
23.676
23.751
23.376
23.5
26
1.5
24.612
24.676
24.751
24.376
24.5
27
1.5
25.612
25.676
25.751
25.376
25.5
28
1.5
26.612
26.676
26.751
26.376
26.5
30
1.5
28.612
28.676
28.751
28.376
28.5
32
1.5
30.612
30.676
30.751
30.376
30.5
33
1.5
31.612
31.676
31.751
31.376
31.5
35
1.5
33.612
33.676
33.751
33.376
33.5
36
1.5
34.612
34.676
34.751
34.376
34.5
38
1.5
35.612
36.676
36.751
36.376
36.5
39
1.5
37.612
37.676
37.751
37.376
37.5
40
1.5
38.612
38.676
38.751
38.376
38.5
42
1.5
40.612
40.676
40.751
40.376
40.5
45
1.5
43.612
43.676
43.751
43.376
43.5
48
1.5
46.612
46.676
46.751
46.376
46.5
50
1.5
48.612
48.676
48.751
48.376
48.5
52
1.5
50.612
50.676
50.751
50.376
50.5
18
2
16.135
16.21
16.31
15.835
16
20
2
18.135
18.21
18.31
17.835
18
22
2
20.135
20.21
20.31
19.835
20
24
2
22.135
22.21
22.31
21.835
22
25
2
23.135
23.21
23.31
22.835
23
27
2
25.135
25.21
25.31
24.835
25
28
2
26.135
26.21
26.31
25.835
26
30
2
28.135
28.21
28.31
27.835
28
32
2
30.135
30.21
30.31
29.835
30
33
2
31.135
31.21
31.31
30.835
31
36
2
34.135
34.21
34.31
33.835
34
39
2
37.135
37.21
37.31
36.835
37
40
2
38.135
38.21
38.31
37.835
38
42
2
40.135
40.21
40.31
39.835
40
45
2
43.135
43.21
43.31
42.835
43
48
2
46.135
46.21
46.31
45.835
46
50
2
48.135
48.21
48.31
47.835
48
52
2
50.135
50.21
50.31
49.835
50
30
3
27.152
27.252
27.382
26.752
27
33
3
30.152
30.252
30.382
29.752
30
36
3
33.152
33.252
33.382
32.752
33
39
3
36.152
36.252
36.382
35.752
36
40
3
37.152
37.252
37.382
36.752
37
42
3
39.152
39.252
39.382
38.752
39
45
3
42.152
42.252
42.382
41.752
42
48
3
45.152
46.252
45.382
44.752
45
50
3
47.152
47.252
47.382
46.752
47
52
3
49.152
49.252
49.382
48.752
49
42
4
38.145
38.27
38.42
37.67
38
45
4
41.145
41.27
41.42
40.67
41
48
4
44.145
44.27
44.42
43.67
44
52
4
48.145
48.27
48.42
47.67
48
-
用于英制螺纹（按ISO 263-1973）的麻花钻直径 —— 统一制粗牙螺纹（UNC）
* 除另有说明外尺寸单位都以毫米计
螺纹
麻花钻
直径
公称直径
in
每吋牙数
螺距
下列等级的小径
2B①
最大
3B
最大
2B和3B①
最小
NO.1
64
0.397
1.582
1.582
1.425
1.55
NO.2
56
0.454
1.872
1.872
1.694
1.85
NO.3
48
0.529
2.146
2.146
1.941
2.1
NO.4
40
0.635
2.385
2.385
2.156
2.35
NO.5
40
0.635
2.697
2.697
2.487
2.65
NO.6
32
0.794
2.896
2.896
2.642
2.85
NO.8
32
0.794
3.531
3.528
3.302
3.5
NO.1O
24
1.058
3.962
3.95
3.683
3.9
NO.12
24
1.058
4.597
4.95
4.343
4.5
1/4
20
1.27
5.268
5.25
4.976
5.1
5/16
18
1.411
6.734
6.68
6.411
6.6
3/8
16
1.588
8.164
8.082
7.805
8
7/16
14
1.814
9.55
9.441
9.149
9.4
1/2
13
1.954
11.013
10.881
10.584
10.8
9/16
12
2.117
12.456
12.301
11.996
12.2
5/8
11
2.309
13.868
13.693
13.376
13.5
3/4
10
2.54
16.833
16.624
16.299
16.5
7/8
9
2.822
19.748
19.52
19.169
19.5
1
8
3.175
22.598
22.344
21.963
22.25
1-1/8
7
3.629
25.349
25.082
24.648
25
1-1/4
7
3.629
28.524
28.258
27.832
28
1-3/8
6
4.233
31.12
30.851
30.343
30.75
1-1/2
6
4.233
34.295
34.026
33.518
34
1-3/4
5
5.08
39.814
39.56
38.951
39.5
2
4-1/2
5.644
45.598
45.367
44.689
45
① 对分数直径包括1级。
-
用于英制螺纹（按ISO 263-1973）的麻花钻直径 —— 统一制细牙螺纹（UNF）
* 除另有说明外尺寸单位都以毫米计
螺纹
麻花钻
直径
公称直径
in
每吋牙数
螺距
下列等级的小径
2B①
最大
3B
最大
2B和3B①
最小
NO.0
80
0.318
1.306
1.306
1.181
1.25
NO.1
72
0.353
1.613
1.613
1.473
1.55
NO.2
64
0.397
1.913
1.913
1.755
1.9
NO.3
56
0.454
2.197
2.197
2.024
2.15
NO.4
48
0.529
2.459
2.456
2.271
2.4
NO.5
44
0.577
2.741
2.741
2.55
2.7
NO.6
40
0.635
3.023
3.012
2.819
2.95
NO.8
36
0.706
3.607
3.597
3.404
3.5
NO.1O
32
0.794
4.166
4.168
3.962
4.1
NO.12
28
0.907
4.724
4.717
4.496
4.7
1/4
28
0.907
5.58
5.563
5.367
5.5
5/16
24
1.058
7.038
6.995
6.792
6.9
3/8
24
1.058
8.626
8.565
8.379
8.5
7/16
20
1.27
10.03
9.947
9.738
9.9
1/2
20
1.27
11.618
11.524
11.326
11.5
9/16
18
1.411
13.084
12.969
12.761
12.9
5/8
18
1.411
14.671
14.554
14.348
14.5
3/4
16
1.588
17.689
17.546
17.33
17.5
7/8
14
1.814
20.663
20.493
20.262
20.4
1
12
2.117
23.569
23.363
23.109
23.25
1-1/8
12
2.117
26.744
26.538
26.284
26.5
1-1/4
12
2.117
29.919
29.713
29.459
29.5
1-3/8
12
2.117
33.094
32.888
32.634
32.75
1-1/2
12
2.117
36.269
36.063
35.809
36
① 对分数直径包括1级。
-
用于不以螺纹作压力密封联接的场合（按GB/T 7307-2001）
* 除另有说明外尺寸单位都以毫米计
螺纹
麻花钻
直径
公称直径
in
每吋牙数
螺距
小径
最大
最小
1/16
28
0.907
6.843
6.561
6.8①
1/8
28
0.907
8.848
8.566
8.8
1/4
19
1.337
11.89
11.445
11.8
3/8
19
1.337
16.395
14.95
15.25
1/2
14
1.814
19.172
18.631
19
5/8
14
1.814
21.128
20.587
21
3/4
14
1.814
24.658
24.117
24.5
7/8
14
1.814
28.418
27.877
28.25
1
11
2.309
30.931
30.291
30.75
1-1/8
11
2.309
35.579
34.939
35.5①
1-1/4
11
2.309
39.592
38.952
39.5
1-1/2
11
2.309
45.485
44.845
45
1-3/4
11
2.309
51.428
50.788
51
2
11
2.309
57.296
56.656
57
① 该数值近似于螺纹大径-螺距。
-
用于以螺纹作压力密封联接的场合（按GB/T 7306.1-2000）
* 除另有说明外尺寸单位都以毫米计
螺纹
麻花钻
直径
公称直径
in
每吋牙数
螺距
小径
最大
最小
1/16
28
0.907
6.632
6.49
6.6①
1/8
28
0.907
8.637
8.495
8.6
1/4
19
1.337
11.549
11.341
11.5
3/8
19
1.337
15.054
14.846
15
1/2
14
1.814
18.773
18.489
18.5
3/4
14
1.814
24.259
23.975
24
1
11
2.309
30.471
30.111
30.25
1-1/4
11
2.309
39.132
38.772
39
1-1/2
11
2.309
45.025
44.665
45
2
11
2.309
56.836
56.476
56.5
① 该数来源于 BSI 1157-75。