Inch sized fasteners and more

Whitworth Pipe Threads

Table for Whitworth pipe thread

Threads per Inch

pilot holeØ mm

Millimeter

Inch Decimal

1/8

28

8,80

9,73

0,3831

1/4

19

11,80

13,16

0,5181

3/8

19

15,25

16,66

0,6559

1/2

14

19,00

20,96

0,8252

5/8

14

21,00

22,91

0,9020

7/8

14

28,25

30,20

1,1890

3/4

14

24,50

26,44

1,0409

1

11

30,75

33,25

1,3091

1.1/8

11

35,50

37,90

1,4921

1.3/8

11

42,00

44,32

1,7449

1.1/2

11

45,50

47,80

1,8819

1.3/4

11

51,40

53,75

2,1610

1.1/4

11

39,50

41,91

1,6500

2

11

57,20

59,62

2,3472