Molding external threads

External threads can be produced in several ways:
- In a mould with the thread in the parting plane
- The thread can be stripped from the mold,
- Unscrewing devices can be used

Mold with the thread in the parting plane

The mold costs can be lowest if the center line of the thread lies in the parting plane of the mold. An expensive external unscrewing device is not necessary in that case. A parting line will however be visible on the surface of the part.

If this is not acceptable, or if the center line of the thread cannot be located in the parting plane, for instance because the center line is in the mold opening direction, the part must be stripped from the mold, or an unscrewing device must be used.

Mold without unscrewing device

Stripped external threads

The principle of stripping external threads of from the mold is shown here. The same considerations as for internal threads apply.

Unscrewing devices for external threads

An example of an unscrewing device for an external threads is shown below.