Whitworthprofiel

Whitworthprofil or Whitworth profile refers to the thread form used in the British Standard Whitworth (BSW) system, a screw thread standard designed by Joseph Whitworth in 1841. It describes the shape of screw threads on fasteners and corresponding nuts that were widely used in British machinery and many colonial products from the late 19th through much of the 20th century.

Characteristics of the Whitworth profile include a V-shaped thread with an included angle of 55 degrees. The crests and roots are rounded rather than sharp, a feature that reduces stress concentrations and aligns with manufacturing practices of the era. The thread’s geometry—pitch, depth, and major diameter—follows the BSW specifications, with the depth and form tied to the pitch. The profile was chosen in part for ease of production with early lathes, taps, and dies.

Historical and current usage: The Whitworth standard was once the dominant form for British machinery, and many older machines, vehicles, and tools still bear BSW fasteners. Since the mid-20th century, global standards have shifted toward metric threads and unified systems, leading to widespread replacement or coexistence with metric equivalents. In restoration projects, original Whitworth fasteners are often reused to preserve authenticity.

Interchangeability: Whitworth threads are not directly compatible with metric or other thread forms due to differences in angle, crest/root shape, and pitch. Correct mating parts must share the same Whitworth profile to ensure proper engagement.