Length of thread ANSI B 2.1

 

 

Nominal Pipe Size

Internal Thread

External Thread

B minimal

L2  minimal

A minimal

mm

inches

inches

inches

mm

inches

1/8

6.5

0.25

0.25

0.2639

9.5

0.38

1/4

8.0

0.32

0.32

0.4018

11.0

0.44

3/8

9.0

0.36

0.36

0.4078

12.5

0.50

1/2

11.0

0.43

0.43

0.5337

14.5

0.56

3/4

12.5

0.50

0.50

0.5457

16.0

0.62

1

14.5

0.58

0.58

0.6828

19.0

0.75

1.1/4

17.0

0.67

0.67

0.7068

20.5

0.81

1.1/2

18.0

0.70

0.70

0.7235

20.5

0.81

2

19.0

0.75

0.75

0.7565

22.0

0.88

2.1/2

23.5

0.93

0.93

1.138

27.0

1.06

3

26.0

1.02

1.02

1.200

28.5

1.12

4

27.5

1.09

1.09

1.300

32.0

1.25