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Whitworth/BSF spanner sizes
See "Spanner Tables" for more information and other imperial and metric sizes

Whit/BSF and the metric or imperial (inch) Equivalent.

 

Imperial to Metric

 

Whitworth

BSF.

Metric.

Imperial (A.F.).

 

A.F

MM.

1/8

3/16

8.64

.340

 

1/4

6.35

3/16

1/4

11.3

.445

 

5/16

7.94

1/4

5/16

13.34

.525

 

3/8

9.52

5/16

3/8

15.24

.6

 

7/16

11.11

3/8

7/16

18.03

.710

 

1/2

12.7

7/16

1/2

20.83

.82

 

9/16

14.29

1/2

9/16

23.37

.92

 

5/8

15.88

9/16

5/8

25.65

1.010

 

11/16

17.46

5/8

11/16

27.94

1.100

 

3/4

19.05

11/16

3/4

30.48

1.200

 

7/8

22.22

3/4

7/8

33.02

1.300

 

15/16

23.81

7/8

1

37.59

1.480

 

1.00

25.40

1

1.1/8

42.42

1.670

 

1.1/16

26.93