The Plate Tilt Problem
Without ejector leader pins, the ejector plate's only guidance comes from the clearance between ejector pins and their through-holes. These holes are sized for ejection clearance (0.01-0.03 mm per side), not for guidance. The result: the plate can tilt during travel, causing pins at the plate edges to contact their holes at an angle.
Consequences of Plate Tilt
- Pin galling: Angular contact creates high local pressure, scoring pin and hole surfaces
- Uneven ejection: Tilted plate pushes some pins further than others
- Pin breakage: Repeated angular loading causes fatigue failure at the pin head
The Solution: Dedicated Ejector Leaders
Ejector leader pins provide H7/g6 guided travel independent of ejector pin clearance. Two or four leader pins at the plate corners keep the entire plate parallel within 0.02 mm across the full stroke — regardless of how many ejector pins are present.