Whitworth Thread (BSW BSF)
Whitworth Thread Profile
- Thread form angle : 55°
- P : Pitch
- n : TPI
- H : Height of fundamental triangle
- h : Height of thread
- r : Radius at the top and bottom of the thread
- D : Major diameter of internal thread
- D1 : Minor diameter of internal thread
- D2 : Pitch diameter of internal thread
- d : Major diameter of external thread
- d1 : Minor diameter of external thread
- d2 : Pitch diameter of external thread
Whitworth Thread Tolerance
- T : Tolerance
- TD1, TD2 : Tolerance for D1, D2
- Td1, Td2 : Tolerance for d1, d2
- ES : Upper deviation of internal thread
- es : Upper deviation of external thread
- EI : Lower deviation of internal thread
- ei : Lower deviation of external thread
- Close, Medium, Free : tolerance class for external thread
- Close, Medium, Normal : tolerance class for internal thread
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
Advertisement
Pitch :
P =
0.000
mm
Height of fundamental triangle :
H =
0.000
mm
Height of thread :
h =
0.000
mm
Radius at the top and bottom of the threads :
r =
0.000
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
| Size | B.S.W. tpi | B.S.F tpi | Whit. S tpi |
|---|---|---|---|
| 1/4 | 20 | 26 | 32 |
| 5/16 | 18 | 22 | 26 32 |
| 3/8 | 16 | 20 | 26 32 |
| 7/16 | 14 | 18 | 26 |
| 1/2 | 12 | 16 | 20 26 |
| 9/16 | 12 | 16 | 20 26 |
| 5/8 | 11 | 14 | 20 26 |
| 11/16 | 11 | 14 | 16 20 26 |
| 3/4 | 10 | 12 | 16 20 26 |
| 13/16 | 12 | 16 20 26 | |
| 7/8 | 9 | 11 | 20 |
| 1 1/16 | 12 20 | ||
| 1 1/8 | 7 | 9 | 12 20 |
| 1 3/16 | 7 | 9 | 12 20 |
| 1 1/4 | 7 | 9 | 12 20 |
| 1 5/16 | 12 20 | ||
| 1 3/8 | 8 | 12 20 | |
| 1 7/16 | 12 20 | ||
| 1 1/2 | 6 | 8 | 12 20 |
| 1 5/8 | 8 | 12 16 20 | |
| 1 3/4 | 5 | 7 | 12 16 20 |
| 1 7/8 | 12 16 20 | ||
| 2 | 4 1/2 | 7 | 12 16 20 |
| 2 1/8 | 8 12 16 | ||
| 2 1/4 | 4 | 6 | 8 12 16 |
| 2 3/8 | 8 12 16 | ||
| 2 1/2 | 4 | 6 | 8 12 16 |
| 2 5/8 | 8 12 16 | ||
| 2 3/4 | 3 1/2 | 6 | 8 12 16 |
| 2 7/8 | 8 12 16 | ||
| 3 | 3 1/2 | 5 | 8 12 16 |
| 3 1/8 | 8 16 | ||
| 3 1/4 | 3 1/4 | 4 1/2 | 8 16 |
| 3 3/8 | 8 16 | ||
| 3 1/2 | 3 1/4 | 4 1/2 | 8 16 |
| 3 5/8 | 8 16 | ||
| 3 3/4 | 3 | 4 1/2 | 8 16 |
| 3 7/8 | 8 16 | ||
| 4 | 3 | 4 1/2 | 8 16 |
| 4 1/8 | 8 16 | ||
| 4 1/4 | 4 | 8 16 | |
| 4 3/8 | 4 8 16 | ||
| 4 1/2 | 2 7/8 | 4 8 16 | |
| 4 5/8 | 4 8 16 | ||
| 4 3/4 | 4 8 16 | ||
| 4 7/8 | 4 8 16 | ||
| 5 | 2 3/4 | 4 8 16 | |
| 5 1/8 | 4 8 16 | ||
| 5 1/4 | 4 8 16 | ||
| 5 3/8 | 4 8 16 | ||
| 5 1/2 | 2 5/8 | 4 8 16 | |
| 5 5/8 | 4 8 16 | ||
| 5 3/4 | 4 8 16 | ||
| 5 7/8 | 4 8 16 | ||
| 6 | 2 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 |
Related topic
How to create a parallel thread profile with CAD software
How to create a 3D model of parallel thread in 3D CAD software