Inner die core / sleeve core insert

* Matched core-and-sleeve design – precision-ground mating clearance (?0.005 mm) ensures concentricity and stable part dimensions, eliminating wobble. * Separate replaceable components – only the worn part (core or sleeve) needs replacement, reducing die maintenance cost by 50-60% vs. one-piece designs. * Core: high-toughness PM steel + TiCN coating – withstands direct punch impact and adhesive wear, ideal for high-strength alloy/stainless steels. * Sleeve: high-strength PM steel + AlCrN coating – resists hoop stress and internal galling, provides rigid support to the core under heavy heading loads. * Interchangeable with standard die holders – quick swap without header re-timing, cutting downtime by 40-50%. * Optimized core/sleeve clearance – allows thermal expansion during high-speed operation (200+ spm) without seizure or loss of precision. * Customizable core diameters and sleeve ODs – adaptable to various part sizes and header makes (National, Sakamura, Hyodong, etc.). * Mirror-finished inner bore (Ra ? 0.08 µm) – ensures smooth part ejection and prevents material pick-up on the core surface. * Optional DLC coating – extends core life 2-4× under abrasive conditions; sleeve with DLC adds extra galling protection. * 100% matched-pair inspection – each core-sleeve set CMM-verified for concentricity, clearance, and hardness (core HRC 58-62, sleeve HRC 56-60); fully interchangeable