Molding internal threads

Internal threads can be molded in several ways:
- Stripped from the mold,
- Collapsible cores,
- Unscrewing devices,
- Hand loaded threaded inserts

Stripped internal threads

The possibility to de-mold parts with internal threads by stripping them from the core is very limited and depends on the plastic type and the thread shape. Only thermoplastics with a low modulus of elasticity and a high yield strain are suitable. During the stripping process the elastic limit must not be exceeded. Rounded threads are especially suited for this option.

Collapsible cores

Collapsible cores are used for smaller parts. Parting lines due to the segments of the split core will appear. Collapsible cores are wear-sensitive.

Unscrewing device for internal threads

High-quality threads can be produced in large production series using unscrewing devices.

Hand loaded threaded inserts

Hand loaded threaded inserts are typically used for small production series and if a high precision is required. The inserts are removed from the mold together with the part.