BSW BRITISH STANDARD WHITWORTH BUTTON DIE

Sutton Tools British Standard Whitworth (BSW) Button Dies are specialized threading tools manufactured from high-quality Carbon Alloy Steel designed for cutting new external threads or chasing existing threads on bolts and studs. These general-purpose round dies are best suited for DIY, workshop maintenance, and non-critical applications involving plastic and non-ferrous metals.

• 1/8" (Major Diameter): The nominal outside diameter of the thread is exactly 1/8 of an inch (approximately 3.175 mm). This produces a very slim, small fastener.
• 40 TPI (Threads Per Inch): The thread pitch consists of exactly 40 individual peaks along one inch of thread length.

• Whitworth Profile: This is a vintage British imperial thread style developed in 1841.
• Flank Angle: It utilizes a 55-degree thread angle with distinctly rounded roots and crests. This differs from modern Metric or Unified (UNC/UNF) threads, which feature a 60-degree angle.

• Form Factor: A solid, round, circular cutting tool featuring internal cutting teeth and clear channels (flutes) for metal chips to escape.
• Sizing Accommodation: It typically features a standard 1-inch Outer Diameter (OD), meaning it fits directly into any common 1" multi-screw button die stock handle or adjustable guide.
• Application: It cuts a male/external thread onto a blank rod or stud. 

• Composition: Built from high-quality Carbon Alloy Steel finished with a bright coating.
• Intended Use: Optimized for general-purpose DIY, workshop maintenance, plastics, and soft non-ferrous metals (like brass, aluminum, or copper).
• Limitation: It is not engineered for hardened structural steels, production line environments, or cutting high-precision, safety-critical aerospace/structural fasteners.