WHITWORTH THREADS (BSW BSF)

Whitworth Thread Profile

BSW Profile

Whitworth Thread Tolerance

W Tolerance

There are three standard series of Whitworth thread :

  • A coarse thread series, the British Standard Whitworth (B.S.W.) Series
  • A fine thread series, the British Standard Fine (B.S.F.) Series
  • A supplementary Selected Thread Series (Whit. S.)

Example of external B.S.W. close class : 1/4-20 B.S.W. (close) bolt

Whitworth Thread Dimension

invalid size
invalid TPI

Pitch diameter tolerance

Major diameter tolerance

Lengths of Engagement (default LE = size)

invalid LE

Result unit

Decimal places

Data not found

Pitch :

P =

0

mm

Height of fundamental triangle :

H =

0

mm

Height of thread :

h =

0

mm

Radius at the top and bottom of the threads :

r =

0

mm

Major diameter (mm)

0.000

0.000

0.000

=

invalid size

Minor diameter (mm)

0.000

0.000

0.000

=

invalid size

Pitch diameter (mm)

0.000

0.000

0.000

=

invalid size

For not specified tolerance, we use the pitch tolerance to calculate the average value.

Whitworth Thread Standard Series

SizeB.S.W. tpiB.S.F tpiWhit. S tpi
1/4202632
5/16182226 32
3/8162026 32
7/16141826
1/2121620 26
9/16121620 26
5/8111420 26
11/16111416 20 26
3/4101216 20 26
13/161216 20 26
7/891120
1 1/1612 20
1 1/87912 20
1 3/167912 20
1 1/47912 20
1 5/16 12 20
1 3/8 812 20
1 7/16 12 20
1 1/26812 20
1 5/8 812 16 20
1 3/45712 16 20
1 7/8 12 16 20
24 1/2712 16 20
2 1/8 8 12 16
2 1/4468 12 16
2 3/8 8 12 16
2 1/2468 12 16
2 5/8 8 12 16
2 3/43 1/268 12 16
2 7/8 8 12 16
33 1/258 12 16
3 1/8 8 16
3 1/43 1/44 1/28 16
3 3/8 8 16
3 1/23 1/44 1/28 16
3 5/8 8 16
3 3/434 1/28 16
3 7/8 8 16
434 1/28 16
4 1/8 8 16
4 1/4 48 16
4 3/8 4 8 16
4 1/22 7/8 4 8 16
4 5/8 4 8 16
4 3/4 4 8 16
4 7/8 4 8 16
52 3/4 4 8 16
5 1/8 4 8 16
5 1/4 4 8 16
5 3/8 4 8 16
5 1/22 5/8 4 8 16
5 5/8 4 8 16
5 3/4 4 8 16
5 7/8 4 8 16
62 1/2 4 8 16
6 1/4 4 8 16
6 1/2 4 8 16
6 3/4 4 8 16
7 4 6 8 12 16