Engineering Insights
Parting and Demolding Direction: Start With How the Part Leaves
The primary demolding direction controls parting, sliders, lifters, ejection, appearance marks, cost, and maintenance.
Choose the main direction
Prefer a direction with practical projected area, clear draft, and direct release from deep cavities. Simple opening directions are usually more stable.
Find undercuts and appearance risks
Side holes, snaps, windows, and reverse steps may require sliders or lifters. Keep parting, gates, and ejector marks away from critical surfaces.
Check shutoff and manufacturability
Parting surfaces need adequate sealing length, steel strength, machining access, and repair space. Thin steel and sharp geometry increase flash and wear risk.