This product is a No.8‑UNC (8‑32) right‑hand split die designed for cutting and repairing external UNC threads on rod, bar and bolt stock. The die body measures 13/16" across and is a round split die intended for use in hand die stocks or machine die holders where controlled, external thread formation or restoration is required.

The die is manufactured from high speed steel (HSS), typically M2 grade, heat‑treated and ground to a precise thread form to retain hardness and cutting edge integrity under heavy use. The thread form is UNC (Unified Coarse), compliant with the Unified thread form as defined by ANSI/ASME B1.1; the nominal thread is No.8 (8‑32 UNC), right‑hand. The split construction gives a small adjustment range to ease setting for repair work and to compensate for minor wear. A light protective finish (black oxide) is applied to resist corrosion during storage and service; note HSS is a tool steel and not stainless, so use light oil or rust inhibitor for long term protection if required.

This split die is suited to workshop and on‑site use in maintenance, fabrication and repair environments. Typical applications include repairing damaged threads on bolts and studs, cutting threads on new shaft stock for prototypes, and producing replacement fasteners in engineering, automotive, marine and plant maintenance. HSS material provides the toughness and red hardness required for cutting mild steel, low alloy steels and some stainless steels (use appropriate cutting fluid), as well as softer materials such as brass and aluminium.

Key benefits include the wear resistance and heat tolerance of M2 HSS for extended tool life, the adjustability of the split design for precise fit and repair, and compatibility with standard UNC fasteners and die stocks. The die’s 13/16" body diameter matches common round die holders, making substitution and tooling straightforward in mixed imperial workshops.

Duchy Fasteners stocks this No.8‑UNC split die individually and as part of imperial die sets. We carry a broad range of HSS split dies in common imperial sizes and pack quantities suitable for trade and workshop use—please contact us for specific size availability and pack options.