This product is a 1/4-20 UNC (13/16in) right-hand split die manufactured from high speed steel (HSS) and designed to cut or restore external Unified National Coarse (UNC) threads on bolts, studs and shafts. The die produces 1/4 inch major diameter threads at 20 threads per inch, with the split construction allowing a small adjustment to fine-tune fit or to chase damaged threads.

Manufactured from M2 grade HSS and supplied with a bright ground finish, the die conforms to the Unified thread form as specified in the Unified Thread Standard (ASME B1.1). It is a round split die with an axial slot and clamping screw arrangement so it can be tightened or relaxed in a standard 13/16in die stock. The right-hand (RH) thread orientation is for conventional right-hand fastening applications.

Typical uses include on-site maintenance, machine repair, plant engineering, automotive restoration and fabrication work where imperial fasteners are present. This die is suitable for cutting and re-cutting threads in a wide range of materials including mild and alloy steels, non-ferrous metals and many stainless steels when used with the appropriate cutting lubricant. It is commonly used by engineers, maintenance technicians, vehicle workshops and marine engineers who need to restore damaged threads or create new external threads to UNC specification.

Key benefits of the HSS split die include wear resistance and elevated hot hardness compared with carbon steel dies, the ability to adjust thread tolerance via the split adjustment, and straightforward compatibility with standard die stocks and handles. While HSS is not stainless, the bright ground finish offers good dimensional stability; use of cutting oil and suitable storage will protect the tool against corrosion.

Duchy Fasteners stocks this 1/4-20 UNC split die individually and as part of imperial die sets. Sizes and pack formats cover common UN series threads; please contact us for availability of single dies, refill packs or full die & stock sets. Our part code for this item is DIEC0025.