The DIN EN 22568 HSS-E Co5 VAP circular dies for metric threads are designed for producing external ISO threads according to DIN 13 on stainless steels, alloy steels, tough steels and materials that are more difficult to machine than standard steels. The HSS-E material with 5% cobalt provides higher heat resistance, wear resistance and cutting-edge stability compared with standard HSS dies, making these tools suitable for more demanding threading operations where profile stability, tool life and consistent thread quality are required.

The VAP surface treatment, obtained by controlled steam tempering, creates an oxidised surface layer that improves lubricant retention and helps reduce seizure and material adhesion. This feature is particularly useful when threading stainless steels and adhesive materials. The 60° profile, 6g tolerance and closed pre-slotted Form B geometry allow accurate and regular external metric threads to be produced in accordance with standard thread fits. The closed Form B design supports stable guidance when the die starts cutting on the workpiece, while the pre-slotted construction helps distribute cutting forces and supports correct thread formation.

These dies are suitable for materials with tensile strength up to approximately 1000 N/mm², including stainless steels, alloy steels, resistant structural steels, heat-treated steels and metallic materials requiring a higher-performance tool than standard HSS-G. They are particularly suitable for mechanical workshops, industrial maintenance, toolrooms, automotive applications, technical fabrication, mechanical engineering and thread repair on components made from demanding materials or subjected to higher operating loads.

The correct version must be selected according to nominal thread size M, pitch, outside die diameter, height and compatibility with the die holder being used. To obtain reliable results, 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.

During machining, progressive cutting with periodic chip breaking is recommended, especially on stainless steels and tough materials. Incorrect workpiece diameter, misaligned starting, unsuitable lubrication or unstable guidance can cause incomplete threads, torn thread profiles, seizure, increased cutting effort, premature die wear and difficult feeding. When used correctly, these dies allow external metric threads to be produced or restored with good accuracy, regular profile quality and improved reliability even on difficult-to-machine materials.