Steel Machine Screws Whitworth

Whitworth machine screws are the imperial-thread fasteners still required for maintenance, repair, and restoration work on older British machinery, vehicles, and equipment manufactured before the metrication of British engineering standards in the 1970s. At the DIY Hardware Store, our Whitworth-sized zinc-plated machine screws are available for the legacy engineering, classic vehicle restoration, and vintage machinery maintenance applications where metric thread screws are not compatible.

The British Standard Whitworth (BSW) thread form uses a 55-degree thread angle and specific thread pitches that are entirely different from the 60-degree ISO metric thread. A metric screw will not engage correctly with a Whitworth-threaded hole, and vice versa - using the wrong thread risks cross-threading, thread stripping, and fastener failure. For anyone working on pre-metric British motorcycles, classic cars, vintage agricultural machinery, or old British industrial equipment, Whitworth screws remain an essential stock item.

Available in the most commonly used BA and BSW thread sizes at the DIY Hardware Store, in zinc-plated steel in the countersunk and pan head formats most frequently needed for legacy machinery maintenance.

  • BSW (British Standard Whitworth) thread form - 55 degree angle
  • Not compatible with metric threads - do not interchange
  • Essential for pre-1970s British machinery and vehicles
  • Used in classic car, motorcycle, and vintage machinery restoration
  • Zinc-plated steel in standard BSW and BA thread sizes
  • Countersunk and pan head formats available