Custom Plastic Injection Molding Services
From Rapid Tooling to Mass Production. We specialize in Insert Molding by combining our in-house precision CNC metal inserts with high-quality polymer molding to deliver fully assembled parts.
Stop managing multiple vendors. 3Q Machining acts as your central manufacturing hub. We CNC machine your internal metal hardware (brass threads, steel pins) and manage the plastic injection tooling to provide a seamless, single-source supply chain. Whether you need 100 units from aluminum prototype molds or 100,000 units from hardened steel tools, we optimize the entire DFM process.
Mold Tooling Strategies
We don't force you into expensive multi-cavity steel molds if you only need 500 parts. We offer a tiered tooling strategy to match your product's lifecycle and budget.
| Tooling Type | Mold Material | Expected Lifespan | Best Used For... |
|---|---|---|---|
| Rapid Tooling (Soft Tool) | Aluminum 7075 / Alumec 89 | 100 - 5,000 shots | Market testing, fast T1 samples (10-15 days), bridging the gap before mass production. |
| Bridge Tooling (SPI Class 103) | P20 Steel / NAK80 | 50,000 - 100,000 shots | Low to mid-volume production, consumer electronics housings. |
| Production Tooling (SPI Class 101) | Hardened H13 / S136 Steel | 1,000,000+ shots | High-volume mass production. Multi-cavity molds with hot runners for ultimate cost efficiency. |
Proactive Defect Prevention (Moldflow Analysis)
| Common Defect | Root Cause | 3Q Machining DFM Solution |
|---|---|---|
| Sink Marks (Surface Depressions) | Uneven wall thickness causes thick sections to cool and shrink slower than thin sections, pulling the surface inward. | We enforce a strict coring and ribbing rule (ribs should be 60% of nominal wall thickness) and optimize holding pressure via Moldflow analysis. |
| Warpage (Bending/Twisting) | Internal stress caused by uneven cooling rates or material shrinkage, especially prominent in Glass-Filled Nylon (PA+GF). | We design conformal cooling channels into the steel tooling to ensure uniform temperature distribution, and adjust gate locations for symmetric flow. |
| Flash (Excess Material on Edges) | Injection pressure exceeds the mold's clamping force, or the parting line of the mold is poorly machined and doesn't seal tightly. | Our injection machines feature oversized clamping tonnage. More importantly, we use Precision Grinding to ensure parting lines mate with zero-gap micron precision. |
Injection Molding Estimator
Balance your upfront tooling investment against long-term part costs. Select your resin, mold class, and production volume to see how multi-cavity tooling drives down your unit price.
The Hybrid Advantage: Insert & Overmolding
As a core CNC machining facility, we possess a unique advantage in plastic injection molding. We seamlessly integrate precision metal hardware into your plastic parts.
Insert Molding (In-House Metal Core)
Need a brass threaded insert or a stainless steel pin embedded in your plastic enclosure? We CNC turn the metal components in-house and mold the plastic around them, ensuring perfect pull-out strength and strict tolerances.
Overmolding (Multi-Material)
We offer overmolding services, molding a soft elastomer (like TPU or Silicone) over a rigid plastic substrate (like PC or ABS) to create ergonomic grips, waterproof seals, and impact-resistant bumpers.
Secondary CNC Post-Machining
Sometimes a feature is too complex to mold directly (e.g., micro cross-holes or extreme undercuts). We mold the near-net shape, then utilize our 5-axis CNC mills to finish the critical micro-features.
Common Resins We Mold
- ABS / PC-ABS: Consumer electronics, strong and impact-resistant.
- Polycarbonate (PC): Clear lenses, durable enclosures.
- POM (Delrin): Low friction gears, medical device handles.
- Nylon (PA6/PA66) + Glass Fiber: Structural automotive parts requiring extreme rigidity.
- PEEK & Ultem: High-temperature aerospace and medical applications.
- TPU / TPE: Overmolded soft grips and seals.
Molding & Tooling FAQ
How much does an injection mold cost and who owns it?
What is your Minimum Order Quantity (MOQ) for molded parts?
Can you assemble the CNC metal parts with the plastic molded parts?
If Aluminum molds are cheaper, why use Steel molds for production?
What is a Draft Angle and why is it necessary?
Consolidate Your Supply Chain
Let us handle both your precision metal internals and your plastic molded housings. Send your 3D CAD files today for a comprehensive DFM quote.
Request Molding QuoteIntegrated Turnkey Ecosystem
Scale your product from one to one million. 3Q Machining integrates precision injection molding with our core CNC insert machining for seamless assemblies.
