This product is a 1 1/2" UNF right-hand split die, designed to cut and repair external fine-pitch inch threads on shafts, studs and bolts. The die is a round, slotted (split) type intended for use in a compatible die stock; the split and adjustable locking screw allow slight size adjustment to compensate for wear or to remove minor thread damage.

Manufactured from M2 high speed steel (HSS), the die offers good hardness and wear resistance for repeated cutting operations. The working surfaces are finished with a black oxide coating to reduce surface corrosion and improve chip release during threading. The thread form produced conforms to the Unified Fine series as defined by ANSI/ASME B1.1 (UN/UNF) and is right-hand handed in its cutting direction. This product is intended for cutting external UNF threads and requires a suitable die stock rather than a drive tool.

Typical applications include maintenance and assembly work in automotive repair, engineering workshops, plant maintenance and general fabrication where imperial fine threads are required. The 1 1/2" UNF size is commonly used where higher tensile clamping and finer adjustment are needed compared with coarse threads; it is therefore seen in specialist engineering, restoration of classic vehicles and heavy machinery maintenance. The split die design is particularly useful for re-threading slightly damaged studs or for achieving a controlled fit on assemblies.

Key benefits of this HSS split die are its durability under repeated use, the ability to re-sharpen HSS if required, and compatibility with standard UNF imperial fasteners. The black oxide finish gives modest corrosion resistance and helps chip evacuation, while the split adjustment provides versatility for repair work or fine-fitting threads. For applications requiring greater corrosion resistance (for example, marine or highly corrosive environments) alternative materials or finishes should be considered.

Duchy Fasteners stocks a comprehensive range of HSS split dies in imperial sizes, available as single items or in boxed packs; please contact us for specific sizes, pack quantities and bulk-order options.