This is a 5/8-11 UNC right‑hand split die manufactured from High Speed Steel (commonly M2), designed for cutting and restoring external unified coarse threads on shafts, studs and rods. Its primary use is to cut new external threads or to chase and repair damaged threads on imperial (inch) components, using a compatible die stock or machine die holder.

The die produces 5/8‑11 UNC threads in the Unified Thread Standard (per ASME/ANSI B1.1), typically yielding a standard Class 2A external fit. The body is a round split‑ring die 1½" in diameter overall length, with a machined chamfer to aid start and a through‑cutting geometry to evacuate swarf. The split design includes an adjustment screw to close or open the cutting face slightly, allowing fine‑tuning of thread engagement and easier correction of undersize or damaged threads.

Made from M2 HSS, the material retains hardness at elevated cutting temperatures and gives good wear resistance compared with carbon tool steels, making it suitable for hand and light machine use. The die is supplied in a bright ground finish which aids cutting accuracy and visual inspection of the thread form. As an imperial UNC die, it is compatible with standard die stocks and holders and will match mating internal threads machined to the Unified standard.

Typical applications include general engineering, maintenance and repair, automotive and agricultural maintenance, fabrication shops, and plant maintenance where imperial threaded repair or prototyping is required. The split die is particularly useful for on‑site repair work where returning components to service quickly is important, and for batch production where small adjustments to thread size are needed without changing tooling.

Key benefits are the HSS material’s wear and heat resistance for longer tool life, the split/adjustable design for restoring or fine‑adjusting threads, and conformity to the UNC/ASME B1.1 thread form for broad compatibility with imperial fasteners. Duchy Fasteners stocks this 5/8‑11 UNC split die in single items and multi‑pack options, and carries a full range of alternative sizes and accessories including die stocks and holders.