Ejector Blades �?With Tip Processing

Three standard tip processing options are available for ejector blades: (1) Flat grind — the most common, removes 0.03–0.05mm from the tip face for a flush ejection surface that eliminates recess marks on the part. (2) Angle cut — the blade tip is ground to a specified angle (typically 5°–15°) to match the draft angle of the rib wall, preventing drag marks during ejection. (3) Step cut — a small step (0.1–0.3mm) is machined into the tip face to create a recess that matches a raised feature on the part (e.g., a positioning boss inside a rib). Custom tip profiles including compound angles are available via special order.

Yes — compound angle machining (angles in two planes simultaneously) is available as a special-order option. This is required when the rib feature has both a longitudinal draft angle and a transverse taper. Standard compound angle combinations include: 3°×5°, 5°×7°, and 5°×10°. The machining is performed on 5-axis CNC to maintain ±0.02mm profile accuracy. Lead time for compound-angle tips is 5–7 business days. Note: compound angles reduce the effective tip contact area, so MISUMI recommends increasing the blade cross-section by one size (e.g., 4×2mm instead of 3×1.5mm) to maintain adequate ejection force distribution.

Tip-processed blade surfaces are held to ±0.02mm for flat grind and angle cut, and ±0.03mm for step cut. Surface finish on the processed tip is Ra 0.4–0.8μm (fine ground), compared to Ra 1.6μm for as-ground (unprocessed) tips. For Class A surface applications where even minor tip marks are unacceptable, a polished finish option (Ra ≤ 0.2μm) is available at additional cost. All tip-processed blades undergo 100% optical inspection with profile measurement recorded on a certificate of conformance included with shipment.