Overmolded cable is a manufacturing technique, not a product category. Rather than terminating a cable with a crimped or soldered connector and leaving the junction mechanical, overmolding encapsulates the joint in injection-molded plastic. Result: a smooth strain relief, weatherproof seal, cosmetic finish, and higher reliability. We run in-house injection molding for cable and connector overmolding — single-shot PVC, 2-shot dual-material, and insert molding across six common materials. This page covers the technique; for product-specific applications, see our waterproof harness, cable assembly, or other relevant pages. MOQ depends on mold amortization — typically 1,000-5,000 pieces for first run.
What Overmolding Actually Does
An overmolded cable starts as a standard cable-plus-connector assembly. Then:
- The pre-terminated connector and cable end are placed into a mold cavity.
- The mold closes. Plastic pellets are melted in the injection machine (190–280 °C depending on material).
- Molten plastic is injected into the closed mold at 500–2,000 bar pressure.
- The plastic flows around the connector body, fills the cavity, and bonds to the cable jacket.
- Cooling (15–45 seconds), then the mold opens and ejects the finished overmolded assembly.
The result is a one-piece assembly with no seams, no gaskets, no aftermarket strain relief. The cable enters the overmold body, encapsulated plastic grips the cable jacket, and the connector terminates cleanly out the other side. Strong, weather-tight, cosmetically consistent.
Single-Shot vs 2-Shot vs Insert Molding
- Single-shot overmolding. One material, one mold injection. Most common and cheapest. Used for USB cables, power cords, and basic industrial connectors. Material choice balances durability, cost, and cosmetic preference.
- 2-shot (dual-material) molding. Two different materials injected in sequence — usually hard plastic inner core for mechanical strength, soft TPE or TPU outer shell for grip. Creates premium-feel handheld products. Requires 2-shot capable tooling; NRE and per-piece cost higher.
- Insert molding. The connector (or complete sub-assembly) is placed into the mold as an “insert,” then plastic is injected around it. This is how USB connectors, sealed automotive connectors, and overmolded metal components are produced. Cycle time is longer because the operator places the insert before each shot.
- Potting as alternative. For low-volume or component-integrated designs, potting (pouring epoxy or polyurethane into a housing) achieves similar environmental sealing without tooling investment. Slower per-piece but no NRE.
Most programs use single-shot or insert molding. 2-shot is specified when the product needs the tactile difference between hard and soft surfaces — consumer handhelds, medical devices with rubberized grips.
Material Selection
| Material | Hardness | Temperature | Best For |
|---|---|---|---|
| PVC | Shore 70-95A | -20 to +85 °C | USB cables, power cords, indoor consumer |
| TPE | Shore 30-90A | -40 to +125 °C | Soft-touch grips, 2-shot outer layer |
| TPU | Shore 60-95A | -40 to +105 °C | Abrasion-resistant outdoor cables, EV charging |
| PU (Polyurethane) | Shore 70-90A | -40 to +105 °C | Industrial drag chain, harsh environments |
| Nylon (PA 6, PA 66) | Shore 70-80D | -40 to +150 °C | Structural connector housings, automotive |
| LSR (Liquid Silicone) | Shore 30-80A | -60 to +200 °C | Medical, food, high-temperature applications |
Material choice drives tooling design — LSR requires different mold steel and runner geometry than PVC. Tell us material preference and we quote tooling accordingly. For programs that might change material later, we sometimes design tooling compatible with multiple materials at extra cost.
Mold Tooling — What It Costs and How It Works
Overmolding requires a custom mold (unless an existing stock mold fits your design). Mold tooling is a one-time NRE investment:
- Single-cavity simple mold — 3,000-6,000 USD. Works for prototypes and low-volume runs up to 5,000 pieces per month.
- Multi-cavity mold (2-4 cavities) — 6,000-12,000 USD. Standard for production volume 10,000-50,000 pieces per month.
- High-cavity mold (8-16 cavities) with hot runner — 15,000-30,000 USD. For high-volume consumer products at 100,000+ pieces per month.
- 2-shot mold — roughly 2x single-material cost due to tooling complexity. Most programs start with single-shot before upgrading.
Tool life is typically 500,000-1,000,000 shots before major maintenance, which means tooling cost amortizes over large volumes. For initial runs, we amortize tooling into per-piece pricing on orders below 5,000 pieces. For programs expecting 50,000+ pieces, the per-piece tooling cost disappears into rounding.
Typical Overmolded Products We Build
Overmolding shows up across most of our product categories. Typical builds:
USB cables. The largest category by volume. 2-shot overmolding with hard inner PVC and soft TPE outer shell is the consumer-premium standard. The USB connector itself is insert-molded — the contact blade assembly is placed in the mold and plastic shot around it. Lightning, USB-C, Micro-USB all use this process.
EV charging cables. Thick TPU overmolding for the connector handle and cable entry. Must survive UV exposure, thermal cycling, mechanical impact, and occasional drops. Single-shot TPU or 2-shot hard shell with softer grip. See our battery harness page for the charging-cable context.
Power adapter cables. The plug and cable junction gets PVC overmold for strain relief and appearance. Common on laptop power adapters, phone chargers, and small appliance cords. Cost-sensitive — single-cavity single-shot tooling typical.
Medical handpieces and device cables. Silicone (LSR) overmolding for biocompatibility and sterilization compatibility. Autoclave and EtO tolerant. See our medical cable assembly page for medical compliance detail.
Automotive sealed connectors. Nylon (PA 6/66) or TPU overmolding on automotive connector assemblies for IP67/IP6K9K sealing. Overmolding eliminates the separate O-ring gasket step. Tooling for Molex MX150, TE Superseal, Deutsch DT connector overmolds is in our library. See our automotive wire harness page for IATF program context.
Industrial M12 and M8 overmolds. Ruggedized overmold on M12/M8 circular connector assemblies for drag chain and factory-floor use. PU overmold for abrasion resistance. See our industrial wire harness page for context.
Branded consumer electronics. Overmolding is often where visible branding appears — color-matched housing, embossed logos, and tactile finishes. For brands that care about cable appearance, overmold color and texture spec is as important as electrical function.
Our Overmolding Capabilities
| Parameter | Capability |
|---|---|
| Injection Machines | 50-ton to 250-ton clamping force |
| Shot Size | 10-400 grams per shot |
| Mold Cavities | 1 to 16 cavities standard, up to 32 on request |
| Cycle Time | 15-60 seconds depending on part size and material |
| Materials Supported | PVC, TPE, TPU, PU, nylon (PA), LSR silicone |
| Process Variants | Single-shot, 2-shot, insert molding, LSR injection |
| Tool Life (typical) | 500,000 to 1,000,000 shots before major maintenance |
| Color Matching | Pantone-matched custom colors (NRE applies) |
| Surface Finish | SPI A1 (high gloss), A3 (matte), textured per customer spec |
| Logo/Embossing | Mold-integrated, no secondary operations needed |
| MOQ (with tooling amortization) | 1,000-5,000 pieces first run |
Why SZFRS for Overmolded Cable Work
In-house injection molding. Vertical and horizontal injection machines from 50 to 250 tons clamping force. We own the process from cable termination through final molding — no subcontracting of the overmold step.
Mold design in-house. We design mold tooling from customer drawings or samples. Typical tooling design takes 1-2 weeks; tool fabrication 3-5 weeks depending on complexity. First article production follows tool completion.
Library of existing tooling. For common connector overmolds (USB-A, USB-C, Molex MX150, M12 variants, DC barrel jacks), we maintain existing tooling that can be reused with your cable spec. This eliminates NRE for standard connector shapes — only cable length and color change per order.
2-shot capable equipment. Dual-material molding for premium consumer products. Material selection optimized for adhesion between the two layers — not all material combinations bond well.
Color matching and branding support. Pantone color matching, custom texture patterns, and logo embossing integrated into mold design. For branded consumer electronics, overmold appearance is the product’s visible surface.
Quality documentation. SPI (Society of Plastics Industry) surface finish classifications, in-process cycle monitoring, and per-lot dimensional inspection. See our quality and certifications page for compliance scope.
Frequently Asked Questions
Can I use an existing mold or do I need new tooling?
Depends on the connector and cable. For standard connectors (USB-A, USB-C, Molex MX150, popular M12 variants), we often have existing tooling that fits — no NRE, faster turnaround. For custom connector shapes, proprietary enclosures, or logo/branding requirements, new tooling is required. Send us photos or drawings and we confirm which path applies.
What’s the difference between insert molding and 2-shot molding?
Insert molding puts a pre-made component (the “insert” — a connector, metal piece, or sub-assembly) into the mold, then plastic is injected around it. Single material. 2-shot molding injects two different materials sequentially in the same mold — first material cools, then second material is injected around it. Different materials, one mold. They can also be combined — insert molding with 2-shot material.
What materials bond well for 2-shot molding?
Most useful combinations use compatible material families. PP + TPE-based compounds bond well. PC + TPU bonds well. PA + TPU bonds. Not all combinations adhere — hard PVC + silicone doesn’t bond without adhesion promoter. Tell us the two materials you want and we verify compatibility or suggest alternatives.
How long does mold tooling take?
Simple single-cavity mold: 3-4 weeks from design approval. Multi-cavity production mold: 5-7 weeks. 2-shot mold: 6-8 weeks. Rush timelines possible with expedited charges. Tool design (1-2 weeks) happens before tool cutting begins, so total kickoff-to-first-article is 5-9 weeks depending on complexity.
Can you match custom colors and branding?
Yes. Pantone-matched colors are standard; color development has a small NRE (typically 300-800 USD) for color matching and material qualification. Logo embossing is integrated into mold design at no extra per-piece cost once tooling exists — the engraving is part of the mold cavity.
Can you do silicone (LSR) overmolding for medical applications?
Yes. LSR (Liquid Silicone Rubber) injection requires dedicated equipment — LSR-specific injection machines with mixing heads for the two-component silicone. Our LSR capability supports medical-grade silicone with USP Class VI and ISO 10993 biocompatibility documentation. See our medical cable assembly page for medical workflow detail.
What’s your MOQ for overmolded cable production?
Depends on tooling investment. With existing tooling: 500 pieces minimum. New tooling with NRE charge upfront: 1,000-5,000 pieces first run, then repeat orders at 500 pieces. For prototype validation before production tooling, we can do soft-tooling prototypes in silicone or 3D-printed mold inserts for 20-50 pieces at higher per-unit cost.
Can you ship overmolded cable internationally?
Yes. Europe, US, India, Southeast Asia, and Middle East regular destinations. Overmolded cables ship safely in standard packaging. DDP, DAP, or EXW per preference.
Related Services and Products
- Custom Manufacturing Overview — full value-added services.
- Waterproof Wire Harness — IP67/68/69K sealed harness applications using overmolding.
- Automotive Wire Harness — sealed automotive connector overmolding.
- Medical Cable Assembly — LSR silicone overmolding for medical devices.
- Cable Assembly — round-cable assembly work often includes overmolded terminations.
Ready to Quote Your Overmolding Project?
Send us the connector, cable spec, target material, expected volume, and any existing sample. We’ll come back with tooling assessment (existing vs new), NRE estimate, and production pricing. Initial quote within 48 hours; detailed tooling proposal within one week.