System

Minimum inner diameter  mm

Outer diameter

mm

Pitch

mm

Unit length

m

Compatible steel tube

  Metric System 

British System

  Thin  steel

Thick steel

φ6

5.7

9

2.7

100

φ8

5/16"

7.7

11.8

4

100

φ10

1/4"

9.7

14.5

4.7

100

#12

1/2"

φ12

3/8"

11.7

16.5

4.7

100

#15

5/8"

#10

3/8"

φ15

1/2"

1.7

20.2

5.7

100

#20

3/4"

#15

1/2"

φ20

3/4"

19.6

24.5

6.4

50

#25

1"

#20

3/4"

φ25

3/4"

19.6

24.5

6.4

50

#32

1/1/4"

#25

1"

φ32

1/1/4"

31.5

39.6

10.5

25

#40

1/1/2"

#32

1/1/4"

φ38

1/1/2"

37.5

46.6

11.4

25

#50

2"

#40

1/1/2"

φ51

2"

49.5

59.6

11.4

20

#70

2/1/2"

#50

2"

φ64

2/1/2"

62.5

74

14.2

10

#80

3"

#70

2/1/2"

φ75

3"

73

85

14.2

10

#80

3"

φ100

4"

97

109

14.2

10

#100

4"

φ125

5’

122

135.5

14.2

5

#125

5"

φ150

6’

146

161.5

14.2

5

#150

6"