What is it?

Hand load (mold) inserts are mold components that are ejected with the molded part and manually removed in order to create undercuts and create threaded features

Typical Method to Product Undercuts

Typically undercuts are created by side actions or core pulls that automatically retract at some point during the molding cycle.  These features can be quite expensive to build and take time.

Pro's and Con's

	Hand Load	Core Pull
Tooling Cost	Cheaper	More Expensive.  Can be very expensive
Time to Build	Faster	Slower
Part Quality	Lower: Seam lines are more pronounced and prone to more flash	Higher: Seam lines are cleaner and less likely to flash
Durability	Lower: Hand loands, especially larger ones, are prone to damage from inserting into the mold or just being dropped.	High: Actions are never removed from the mold.  They are more damage prone than fixed components
Part Cost	Higher: An operator is required by definition and parts run much slower.  If an operator is required for other reasons then this is not an issue.	Lower: Typically runs automatically and quite fast.

When to use Hand Loads:

Use hand loads when tool cost or time to market is important or when part features cannot be produced any other way.

Use core pulls and side actions when part cost and quality are primary concern.

Example

In this example the green hand load insert (green) produces the threaded feature of the part ( purple).  The insert is unscrewed manually by an operator after ejection.  Multiple inserts are used so that a new part can be molded while the other is unscrewed.  In a traditional mold and expensive unscrewing mechanism would be employed.