Whitworth socket screws, also known as BSW (British Standard Whitworth) are a type of high tensile fastener using a thread developed in the 19th century in the United Kingdom. They have a distinctive thread profile with a 55-degree thread angle with rounded crests and roots.
Whitworth socket screws have a hexagonal recess designed to be used with a socket wrench or allen key, offering a secure fastening.
The Whitworth thread use has diminished over time however some older equipment or vintage applications still use them. Types include socket cap screws, socket button screws and countersunk (CSK) socket screws. Finished include zinc, stainless and unplated self colour.
Size options we stock include 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 3/4", 7/8", 1", 1 1/8", 1 1/4"