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Thread Identification Chart

National Pipe, British Pipe, and SAE Thread Configurations

 

Sizes

National Pipe Thread

SAE 37” and O-Ring Boss

Imperial Compression

O-Ring Face Seal

SAE 45” Flare / J512

Inverted Flare / J512

British Pipe Thread

Dash Size

Inch Size

NPTF Pipe

Threads Per Inch

SAE Thread

Threads Per Inch

ERMETO Flareless

Threads Per Inch

OFS Thread

Threads Per Inch

SAE 45” Thread

Threads Per Inch

Inverted Flare

Threads Per Inch

BSP British

Threads Per Inch

-2

1/8

1/8

27

5/16

24

5/16

24

 

 

5/16

24

5/16

28

1/8

28

-3

3/16

 

 

3/8

24

3/8

24

 

 

3/8

24

3/8

24

 

 

-4

1/4

1/4

18

7/16

20

7/16

20

9/16

18

7/16

20

7/16

24

1/4

19

-5

5/16

 

 

1/2

20

1/2

20

 

 

1/2

20

1/2

20

 

 

-6

3/8

3/8

18

9/16

18

9/16

18

11/16

16

5/8

18

5/8

18

3/8

19

-7

7/16

 

 

 

 

 

 

 

 

11/16

16

11/16

18

 

 

-8

1/2

1/2

14

¾

16

¾

16

1 3/16

16

¾

16

3/4

18

1/2

14

-10

5/8

 

 

7/8

14

7/8

14

1

14

7/8

14

7/8

18

 

 

-12

¾

3/4

14

1 1/16

12

1 1/16

12

1 3/16

12

1 1/16

14

1 1/16

16

3/4

14

-14

7/8

 

 

1 3/16

12

1 3/16

12

 

 

1 1/4

12

1 3/16

16

 

 

-16

1

1

11 1/2

1 5/16

12

1 5/16

12

1 5/16

12

1 3/8

12

1 5/16

16

1

11

-20

1 1/4

1 1/4

11 1/2

1 5/8

12

1 5/8

12

1 11/16

12

 

 

 

 

1 1/14

11

-24

1 1/2

1 1/2

11 1/2

1 7/8

12

1 7/8

12

2

12

 

 

 

 

1 ½

11

-32

2

2

11 ½

2 1/2

12

2 1/2

12

 

 

 

 

 

 

2

11

-40

2 1/2

2 1/2

 

3

12

3

12

 

 

 

 

 

 

 

 

-48

3

3

 

3 1/2

12

3 1/2

12

 

 

 

 

 

 

 

 


National Pipe, British Pipe, and SAE Thread Configurations

LL

L

S

 

German Super Light

German Light

German Heavy

French

Tube

Thread

Tube

Thread

Tube

Thread

Tube

Thread

4MM

M8 x 1.0

6MM

M12 X 1.5

6MM

M14 x 1.5

12MM

M18 x 1.5

5MM

M10 x 1.0

8MM

M14 X 1.5

8MM

M16 x 1.5

13.25MM

M20 x 1.5

6MM

M10 x 1.0

10MM

M16 X 1.5

10MM

M18 x 1.5

16.75MM

M24 x 1.5

8MM

M12 x 1.0

12MM

M18 X 1.5

12MM

M20 x 1.5

21.25MM

M30 x 1.5

10MM

M14 x 1.0

15MM

M22 X 1.5

14MM

M22 x 1.5

26.75MM

M36 x 1.5

12MM

M16 x 1.0

18MM

M26 X 1.5

16MM

M24 x 1.5

33.50MM

M45 x 1.5

 

 

22MM

M30 X 2.0

20MM

M30 x 2.0

 

 

 

 

28MM

M36 X 2.0

25MM

M36 x 2.0

 

 

 

 

35MM

M42 X 2.0

30MM

M42 x 2.0

 

 

 

 

42MM

M52 X 2.0

38MM

M52 x 2.0

 

 

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