This is a 12 mm x 1.75 right‑hand (RH) split die manufactured from high speed steel (HSS) for cutting and repairing external metric threads. It is designed to produce standard ISO metric threads (M12 × 1.75) on round bar, studs and shafts, and is suitable for hand use in a die stock or light machine work in a die holder. The die has an approximately 1" outer diameter to suit common die holders and chucks.

Manufactured from M2 grade high speed steel with a ground cutting profile, the split construction allows the two halves to be adjusted slightly to alter thread fit or to compensate for wear. The die cuts the ISO metric thread form in accordance with ISO 261/965 and the commonly used DIN 13 profile, producing a right‑hand, coarse‑pitch M12 thread. The tool is supplied in a bright/ground finish; some variants are supplied with a light protective coating such as black oxide to reduce surface corrosion during storage.

The HSS material and heat treatment give the die greater hot hardness and toughness than carbon steel dies, making it appropriate for cutting mild and alloy steels, stainless steels, brass, bronze and aluminium. It is an excellent choice for workshop maintenance, engineering fabrication, agricultural and automotive repairs where occasional or intermittent external threading is required. For best results use an appropriate cutting lubricant, a die stock or holder that centres the die, and advance in small increments with periodic backing off to break chips.

Key benefits of the split HSS die include improved corrosion resistance when coated, higher wear resistance and cutting life from the M2 HSS grade, and adjustable thread fit through the split design allowing fine tuning between a looser or tighter fit. It is compatible with standard die holders and the metric fastener system, making it straightforward to integrate into existing tooling sets.

Duchy Fasteners stocks split dies across the metric range, available as individual pieces and in boxed sets. Sizes typically cover the common metric series (for example M3 to M24) and are supplied in single units or multi‑pack sets to suit workshops and maintenance teams.