This 3/8" x 20 BSF Chrome Alloy Die Nut is designed for repairing, restoring, and forming British Standard Fine (BSF) external threads in situations where a button die cannot be used due to limited workspace or on-site access constraints.

Key Features:

• Thread Standard: British Standard Fine (BSF), a finer-pitch adaptation of the British Standard Whitworth (BSW) thread form.
• Versatile Use:
  • Acts as a thread chaser for cleaning and restoring worn or damaged threads.
  • Capable of cutting new male threads on non-ferrous metals and plastics.
• Material: Chrome alloy construction suitable for general-purpose threading (not intended for precision, structural, or safety-critical applications).
• Thread Form Details:
  • Finer thread pitch results in increased tensile stress area compared to coarse threads of the same size.
  • Provides better resistance to thread stripping under high load.
  • Ideal for applications where limited thread engagement or thin wall sections require a fine pitch.
  • BSF thread form introduced in 1908 and standardised in BS84:1956.

Technical Specifications:

• Diameter (inch): 3/8
• Pitch (TPI): 20
• Thread Form: BSF

Applications:

BSF threads are widely used in machinery restoration, automotive work, engineering assemblies, and classic equipment where fine-thread fasteners offer improved strength and durability. This die nut is ideal for thread repair, fabrication, maintenance, and general-purpose external thread cutting.