The DIN EN 22568 HSS-G fully ground circular dies for UNC threads are designed for producing external American Unified National Coarse threads according to ANSI B1.1 on rods, pins, studs, special screws, mechanical components and parts requiring thread repair. UNC threads, with their coarse pitch compared with fine-thread series, are widely used in mechanical applications, industrial maintenance, automotive work, technical fabrication, equipment and machinery built to American or inch-based standards.

The fully ground HSS-G high-speed steel construction provides accurate cutting geometry, stable thread profile and consistent thread quality. Grinding improves cutting-edge regularity compared with non-ground tools, supporting smoother feed, better profile control and repeatable machining results. The 60° profile, 2A tolerance and closed pre-slotted Form B geometry allow controlled external UNC threads to be produced in accordance with standard thread fits. The closed Form B design provides stable guidance when the die starts cutting on the workpiece, while the pre-slotted construction helps distribute cutting forces and supports regular thread formation.

These dies are suitable for materials with tensile strength up to approximately 800 N/mm², including structural steels, unalloyed steels, free-cutting steels, mild steels and general metallic materials compatible with HSS-G cutting tools. They are particularly useful for producing or restoring UNC threads on maintenance components, industrial spare parts, fasteners, threaded pins and mechanical parts where inch-based American threading standards must be respected.

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 or insufficient lubrication can cause incomplete threads, torn thread profiles, increased cutting effort, premature die wear and difficult feeding. During machining, progressive cutting and periodic chip breaking are recommended, especially on larger diameters and tougher materials. These dies are suitable for mechanical workshops, maintenance technicians, toolrooms, production departments, automotive applications, industrial repair and machining of components with UNC standards, where precision, reliability and compatibility with American threads are required.