Overmoulding & Insert Moulding

Our rapid overmoulding and insert moulding processes produce custom prototypes and on-demand production parts in as fast as 15 days. We use aluminium moulds that offer cost-efficient tooling, producing parts from a range of thermoplastic and liquid silicone rubber materials.

Overmoulding and Insert Moulding design guidelines will help you understand capabilities and limitations 

Why Choose Overmoulding Or Insert Moulding For Your Project?

While overmoulding requires more complex design, processing, and materials choice than single-shot injection moulding, it offers significant benefits:

  • It allows materials to be combined to provide characteristics that no single resin can deliver.
  • It can eliminate assembly steps, saving both time and money.
  • It can meld materials in a way that assembly processes cannot match.
  • Inserts add strength and durability to parts.

We offer a number of additional moulding and tooling services to support your project.

How Does Overmoulding And Insert Moulding Work?

With overmoulding, the production of the substrate parts is a standard injection moulding process involving an aluminium mould with no heating or cooling lines running through it. Cycle times are a bit longer, which allows our moulders to monitor fill pressure, cosmetic concerns, and the basic quality of the parts.

When the total run of substrate parts are moulded, overmould tooling is then assembled to the press. The substrate parts are placed by hand into mould where each part is overmoulded with either a thermoplastic or liquid silicone rubber material.

Insert moulding is a similar process but instead uses a preformed part—often metal—that is loaded into a mould where it is then overmoulded with plastic to create a final component. When the run is complete, parts are boxed and shipped shortly thereafter.

injection moulding icon

25 to 10,000+

Shipped in 15 days or less



Best For:
  • on-demand production
  • bridge tooling
  • pilot runs
  • rapid prototyping

Overmoulding Materials and Inserts

We stock a range of thermoplastic and LSR materials for overmoulding that are suitable for various part applications and industries. Customer-supplied metal inserts are also accepted.



Design Guidelines

Our basic guidelines for overmoulding and insert moulding include important design considerations to help improve part manufacturability, enhance cosmetic appearance, and reduce overall production time.


press operator examines liquid silicone rubber part

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