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 secondary services to support your project.

How Do 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.

IM icon Logo
  • 25 to 10,000+
  • Shipped in 15 working days or less
Common Applications
  • low-volume production
  • bridge tooling
  • pilot runs
  • functional prototyping


Watch: Injection Moulding

Rapid injection moulding works best for on-demand production, bridge tooling, pilot runs, and functional prototyping. Our affordable aluminium moulds and quick turnaround times help reduce design risks and limit overall production costs.


Watch: ProtoQuote with Design Analysis (UK)

Product designers and engineers can upload a 3D CAD model online at any time to receive an interactive ProtoQuote® with free design for manufacturability (DFM) analysis and real-time pricing information within hours. The DFM analysis helps eliminate potential problems like sink, challenging undercuts or walls that are too thin or thick. Once a part design is ready and a quote approved, production begins almost immediately. Upload a part today for a ProtoQuote with design analysis.

Design Guidelines: Overmoulding & Insert Moulding

press operator examines liquid silicone rubber part

Free mouldability analysis within hours