尺寸代號

每25.4mm類的牙數(shù)n

螺距p

牙型高度h

圓弧半徑r≈

基面上的基本直徑

基準(zhǔn)距離

有效螺紋長度

大徑（基準(zhǔn)直徑）d=D

中徑d2=D2

小徑d1=D1

1/16

28

0.907

0.581

0.125

7.723

7.142

6.561

4.0

6.5

1/8

28

0.907

0.581

0.125

9.728

9.147

8.566

4.0

6.5

1/4

19

1.337

0.586

0.184

13.157

12.301

11.445

6.0

9.7

3/8

19

1.337

0.586

0.184

16.662

15.806

14.950

6.4

10.1

1/2

14

1.814

1.162

0.249

20.955

19.793

18.631

8.2

13.2

3/4

14

1.814

1.162

0.249

26.441

25.279

24.117

9.5

14.5

1

11

2.309

1.479

0.317

33.249

31.770

30.291

10.4

16.8

1.1/4

11

2.309

1.479

0.317

41.910

40.431

38.952

12.7

19.1

1.1/2

11

2.309

1.479

0.317

47.803

46.324

44.845

12.7

19.1

2

11

2.309

1.479

0.317

59.614

58.135

56.656

15.9

23.4

2.1/2

11

2.309

1.479

0.317

75.184

73.705

72.226

17.5

26.7

3

11

2.309

1.479

0.317

87.884

86.405

84.926

20.6

29.8

3.1/2

11

2.309

1.479

0.317

100.330

98.851

97.372

22.2

31.4

4

11

2.309

1.479

0.317

113.030

111.551

110.072

25.4

35.8

5

11

2.309

1.479

0.317

138.430

136.951

135.472

28.6

40.1

6

11

2.309

1.479

0.317

163.830

162.351

160.872

28.6

40.1