* 除另有說明外尺寸單位都以毫米計(jì)

螺紋

麻花鉆

直徑

公稱直徑

in

每吋牙數(shù)

螺距

下列等級(jí)的小徑

2B^①

最大

3B

最大

2B和3B^①

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 對(duì)分?jǐn)?shù)直徑包括1級(jí)。

* 除另有說明外尺寸單位都以毫米計(jì)

螺紋

麻花鉆

直徑

公稱直徑

in

每吋牙數(shù)

螺距

下列等級(jí)的小徑

2B^①

最大

3B

最大

2B和3B^①

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 對(duì)分?jǐn)?shù)直徑包括1級(jí)。