Get custom plastic parts molded with two materials or metal inserts.
Our overmolding process produces custom prototypes and on-demand production parts in as fast as 15 days. We use aluminum molds that offer cost-efficient tooling, producing parts from a range of thermoplastic and liquid silicone rubber materials.
Our basic guidelines include important design considerations to help improve part manufacturability, enhance cosmetic appearance, and reduce overall production time.
Height may be limited if using a silicone as the overmold material, and deeper parts are limited to a smaller outline.
Minimum part volume is 0.025 cu. in. (40.98 cu. mm).
With substrate molds, we can maintain a machining tolerance of ±0.003 in. (0.08mm) with an included resin tolerance that can be greater but no less than 0.002 in./in. (0.002mm/mm).
With thermoplastic overmolds, tolerances remain the same as substrate molds, however, if the overmold is LSR, then tolerances shift to 0.025 in./in. (0.025mm).
Chemical bonding between overmolded materials is possible, but material compatibility should be considered in order to achieve desired bond strength. Incorporation of an adequate mechanical bond is strongly recommended if bonding is critical to your application.
| Overmold Material | ABS | ABS/PC CYCOLOY C2950-111 | PC Lexan940-701 | PBT Valox357-1001 | PP Profax 6323 |
|---|---|---|---|---|---|
| TPU - Texin 983-000000 | C | C | C | C | M |
| TPV - Santoprene 101-87 | M | M | M | M | C |
| TPE - Santoprene 101-64 | M | M | M | M | C |
| LSR - Elastosil 3003/30 A/B | - | - | M | M | - |
| TPC - Hytrel 3078 | C | C | C | C | M |
| TPE-Versaflex OM 1060X-1 | C | C | C | M | M |
| TPE-Versaflex OM 6240-1 | M | M | M | M | M |
| TPE-Versaflex OM 6258-1 | M | M | M | M | M |
| TPE-Versaflex OM 1040X-1 | C | C | C | M | M |
With overmolding, the production of the substrate parts is a standard injection molding process involving an aluminum mold with no heating or cooling lines running through it.
Standard injection molding process with aluminum molds
Monitor fill pressure, cosmetic concerns, and basic part quality
Assembly of overmold tooling to the press
Substrate parts placed by hand into mold
Overmolding with thermoplastic or liquid silicone rubber material
Learn what product designers must consider when designing a part for injection molding
Best practices for adding a second molded part to an existing part
Technical overview of thermoplastic and elastomer materials
Combining rigid and flexible materials with 3D printing
Contact our expert team for free quotation and professional technical consultation. We look forward to helping you create excellent products.
Professional CNC machining and custom parts manufacturing services, meeting your precision machining needs with rapid delivery of high-quality components.
© 2025 Partsproto | All rights reserved.
