The DIN EN 24231 HSS-G fully ground circular dies for G BSP threads are designed for producing external cylindrical Whitworth threads according to DIN ISO 228/1 on pipes, fittings, nipples, adapters, hydraulic components, pneumatic parts and mechanical components intended for non-tapered threaded connections. The G BSP thread, also known as BSPP, is a cylindrical pipe thread with a 55° Whitworth profile, widely used in industrial connections, plant engineering, fluid circuits, mechanical maintenance and technical applications requiring compatibility with parallel gas thread standards.

The fully ground HSS-G high-speed steel construction provides accurate cutting geometry, stable thread profile and consistent thread quality. The ground cutting edges allow smoother machining compared with non-ground tools, improving die feed, profile cleanliness and thread repeatability. The 55° profile and closed pre-slotted Form B geometry allow regular and controlled external G BSP threads to be produced, while maintaining good tool guidance when starting on the workpiece. The pre-slotted construction helps distribute cutting forces and supports correct Whitworth profile formation.

These dies are suitable for materials with tensile strength up to approximately 800 N/mm², including structural steels, unalloyed steels, mild steels, free-cutting steels, brass, bronze and metallic materials compatible with HSS-G cutting tools. They are particularly useful for mechanical workshops, maintenance technicians, plant installers, production departments, toolrooms, hydraulics, pneumatics, industrial piping and thread repair on fittings or components with G BSP standards. Since G threads are cylindrical and not tapered, sealing is generally achieved by means of a gasket, washer, shoulder or dedicated sealing element, rather than by tapered thread interference.

The correct version must be selected according to G BSP size, pitch in threads per inch, outside die diameter, die height and compatibility with the die holder being used. It is important to correctly distinguish cylindrical G BSP threads from tapered BSPT threads or other inch-based standards, because thread profile, sealing function and fit may differ.

To obtain accurate threads, the external workpiece diameter must be prepared correctly, a suitable starting chamfer must be made, the die must be kept coaxial and perpendicular to the component axis, and appropriate cutting lubricant must be used. Incorrect workpiece diameter, misaligned starting, insufficient lubrication or unstable guidance can cause incomplete threads, torn profiles, increased cutting effort, premature die wear and poor engagement with female fittings or components. During machining, progressive cutting and periodic chip breaking are recommended, especially on larger sizes or tougher materials.