Example designation
0.25-20 B.S.W.,(close) bolt
- 0.25
- Nominal major diameter in inches.
- 20
- Threads per inch.
- B.S.W.
- British Standard Whitworth designation.
- (close) bolt
- Close external fit; the nut has a separate fit selection.
55° changes the inspection geometry
The rounded profile and 55° included angle affect thread height and measurement over wires. Use the Whitworth wire result for the selected pitch when setting up inspection.
Bolt and nut fits have different names
External choices are Free, Medium, and Close. Internal choices are Normal, Medium, and Close. Set both explicitly, along with the engagement length required for the part.