This site will look much better in a browser that supports web standards, but it is accessible to any browser or Internet device.


Clubs, glossaries, museums, shops and much more......

glue-it.com

...all of your model making needs from one site.







British Standard Whitworth (BSW)

A symmetrical V thread with an angle between the threads measured in the axial plane of 55. 1/6 of the V, i.e. the point is truncated with arcs blended tangentially into the flanks. The following table lists tapping and clearance drill sizes in imperial and metric.


 

 

Tapping Drill

Clearance Drill

Dia. in

TPI 

inches

mm

inches

mm

1/16

60

0.0413

1.05

 

 

3/32

48

0.077

1.95

 

 

1/8

40

0.104

2.65

9/64

3.57

5/32

32

0.13

3.3

 

 

3/16

24

0.154

3.9

13/64

5.16

7/32

24

0.185

4.7

 

 

1/4

20

0.209

5.3

17/64

6.75

5/16

18

0.264

6.7

21/64

8.3

3/8

16

0.323

8.2

25/64

9.9

7/16

14

0.374

9.5

29/64

11.5

1/2

12

13/32

10.7

33/64

13.1

9/16

12

15/32

12.4

37/64

14.7

5/8

11

33/64

13.8

41/64

16.3

3/4

10

5/8

16.75

49/64

19.5

7/8

9

47/64

19.5

57/64

22.6

1

8

27/32

22.5

11/64

25.8

11/8

7

61/64

24.2

19/64

29.0

11/4

7

15/64

27.4

117/64

32.2

11/2

6

119/64

32.9

133/64

38.5

2

41/2

147/64

44.1

21/64

51.2

See also: British Association Threads.