7mm fin die

Progressive fin stamping die, model Φ7.3mm×24R×2P, built for an AK85 open-type fin press (Aomate, Ningbo). Fin specification: 21mm hole pitch within a row, 12.7mm width (single row), Φ7.30mm ±0.05mm fin hole, staggered pattern, plain fin surface, stamped in continuous strips of 4 to 52 holes per fin length. Compatible material: China-representative O-temper or H22 hydrophilic aluminum foil (elongation >20%), 0.11mm thick, 315mm stock width. Collar height is adjustable from 1.4mm to 1.9mm at this thickness. Punching process (10 stages): Drawing → Piercing/Extruding and Drawing → Louver → Re-flaring → Notching 1 → Notching 2 → Edge trimming → Row slitting → Feeding → Straight cut-off. 1. Drawing — completed in multiple steps, each independently height-adjusted via a SIKO regulator on the die. 2. Piercing/extruding and drawing — punching completes first as the press slide descends, then drawing finishes on the same stroke. The piercing sub-die uses an independent guide-post/guide-bush structure for forming precision and long service life; punch-to-die concentricity is held within 0.002mm for full interchangeability. Punches are air-purged in both directions with automatic mist lubrication for forced scrap discharge. 3. Louver — forms louvered slits across the fin surface to improve airside heat transfer. 4. Re-flaring — collar height adjusts arbitrarily via the same SIKO regulator. 5–6. Notching 1 and 2 — cut the custom notch shapes called for on the fin drawing. 7. Edge trimming — an independent structure trims excess edge material with a slug-retention feature to maximize cutting-edge life. 8. Row slitting — upper and lower blades cut 1 to 6 rows of fins in a pop-up, quick-switch cartridge; the upper plate is engraved 1–23 across for fast row-count changes, with a controlled blade gap for clean, burr-free strips. 9. Feeding — a pull-type feed uses fine grippers seated in the formed holes, driven by a connecting rod between die and press; feeding fingers are SKD11 tool steel for accurate long-run, high-speed positioning. 10. Straight cut-off — length-wise cutoff via cylinder, solenoid valve and the press's electrical control, with oil-free lubrication at the cut face; an independent adjustment sets each row's fin curvature, and cut-off position can shift half a pitch for precise, collision-free hole alignment. Build quality: piercing punch/die, row-cutting, edge-trim and cut-off blades are ASP30 tool steel from Sweden at HRC62–64; the louver punch/die is ASP30 at HRC60–62. Upper/lower plates are P20 pre-hardened steel (China); the station set, punch/die fixing plate and stripper are PDS5 pre-hardened steel (Japan). Quality assurance: 12-month warranty from delivery, with lifetime paid maintenance available. Punching parts are guaranteed for 25 million+ strokes on aluminum foil before resharpening, with up to 10 regrinds over the die's service life. Normal working speed is 150–210 SPM.