DIY Stamping Dies: Kirksite & Urethane
锌合金与聚氨酯简易冲模自制
标签：自制冲模, 锌合金, 聚氨酯模, 低成本
零星冲压件的两类自制模：①锌合金复合模——Zn-Al4 合金 380 °C 铸出凸凹模，硬度 HB 100–120，冲 0.5–1.5 mm H62 带料可用 5000–20000 冲次，铸后仅需钳工修配间隙，成本约为钢模 1/5，单边间隙按料厚 8% 钳配；②聚氨酯冲裁模（Sanford 工艺）——凸模 T8 钢淬火 HRC 55，"凹模"为 30 mm 厚邵氏 A85 聚氨酯板，适合 ≤0.3 mm 紫铜薄片落料，无毛刺但轮廓边缘有 0.1–0.2 mm 圆化，适用铭牌与饰片。两种模具都适合作为实习教学课题。
Two DIY dies for occasional parts: (1) kirksite compound dies — cast punch and die from Zn-Al4 at 380 °C, HB 100–120, good for 5,000–20,000 strokes on 0.5–1.5 mm H62 strip; fitter-fit the clearance at 8% of gauge per side at a fifth of steel tooling cost. (2) Urethane blanking (Sanford process) — a hardened T8 punch (HRC 55) working against a 30 mm Shore-A 85 urethane pad, ideal for ≤0.3 mm copper sheet; burr-free but the profile softens by 0.1–0.2 mm, fine for nameplates and trim. Both make excellent student projects.