This product is a 3/4" BSW (British Standard Whitworth) right-hand split die with a 1 1/2" round body, designed for cutting, re‑threading and sizing external Whitworth threads. It is intended for use in a compatible die stock/holder to produce or restore 3/4" BSW threads on bolts, studs and shafts where the Whitworth 55° rounded thread form is required.

The die is manufactured from M2 high‑speed steel (HSS), bright ground and hardened to provide long cutting life and good wear resistance. The part conforms to the Whitworth thread form as defined by BS 84 (British Standard Whitworth), with a right‑hand thread orientation. As a split die, it includes an adjustable split which allows a small amount of size correction and easier entry on worn or slightly oversize material; it is intended to be used with a standard 1 1/2" round die stock/holder sized for Whitworth dies.

Typical applications include restoration and maintenance of older British machinery, vintage automotive and motorcycle repair, agricultural and tractor work, rail and marine maintenance where Whitworth fasteners are still used, and general engineering workshops that deal with imperial thread standards. The die is suitable for cutting on mild steel, medium carbon steels and similar ferrous materials when used with appropriate cutting lubricant.

Key benefits of this M2 HSS split die are its high hot‑hardness and wear resistance, which maintain cutting performance over prolonged use, and the adjustability provided by the split design for improved thread fit. While HSS gives excellent strength and edge retention, it is not a stainless material; the bright finish will resist light corrosion, but users should apply cutting oil during use and store the die dry or oiled to prevent rust. The die is compatible with standard Whitworth die stocks and follows common imperial sizing conventions for easy replacement or integration into workshop toolsets.

Duchy Fasteners stocks a broad range of imperial dies and taps including Whitworth sizes; this split die is available individually and we hold varied sizes and pack quantities to suit workshop and trade requirements. Please contact us for current availability and pack options.