This product is an 18 mm x 2.5 mm right‑hand split die manufactured from HSS for cutting or restoring external ISO metric threads on round bar and studs. Its primary use is cutting M18 × 2.5 external threads and chasing damaged threads where a controlled fit is required; the split design allows a slight adjustment of cut to suit the workpiece or to compensate for wear.

The die body is manufactured from M2 high‑speed steel (HSS), heat treated for cutting durability and finished with a black oxide coating to reduce light surface corrosion and help chip evacuation. It produces ISO metric thread form (ISO 68‑1) with a standard pitch of 2.5 mm and is compatible with ISO 261/ISO 965 and BS 3643 thread specifications; typical external tolerance class produced is 6g when set in a standard die stock. This is a right‑hand thread die intended for use in hand die stocks or compatible machine die heads; the split aperture and adjusting screw permit fine setting of thread engagement. Suitable cutting fluids should be used, particularly when machining stainless steels or hardened materials.

Typical applications include on‑site maintenance and repair of bolts, studs and shafts, small‑batch production of external threads, and recovery of damaged threads in automotive, plant maintenance, fabrication and mechanical engineering workshops. The die is also used in rail, marine and oil‑and‑gas maintenance where reinstating a reliable threaded connection is required. It is suitable for use on mild and alloy steels, stainless steels (with appropriate lubricant), brass, aluminium and many technical plastics.

Key benefits of the split HSS die are its adjustability to tailor thread fit, the wear resistance and edge retention of M2 HSS for extended service life, and compliance with international metric thread standards for interchangeability. The black oxide finish aids corrosion resistance compared with untreated tool steel, though it is not a stainless product so storage and lubrication are recommended for long life.

Duchy Fasteners stocks a comprehensive range of metric HSS split dies in popular sizes and supplies them as single pieces or in multi‑pack quantities to suit workshop and production requirements. If you need other sizes or matching die stocks, please contact our sales team.