In-House Overmolding & Injection Molding for Cable Assemblies

Three problems solved in one shot, or none of them.

HKWIRE is a custom cable assembly manufacturer and OEM/ODM supplier in Longgang, Shenzhen — and overmolding is done in-house. The tool room, the molding floor and the assembly lines share one facility, which is what lets us hold exit geometry, sealing and cycle time to the numbers we quote.

Overmolding solves three problems at once: it locks the connector to the cable, it controls where the cable bends, and it is the only realistic way to make an interface survive a wet, oily or high-vibration environment. Done badly it does none of these, and adds a failure point where there was none.

Material selection.

An overmolding line you can audit

We are a manufacturer, not a sourcing desk. Overmold tooling is designed and cut in our own tool room — the shelves below hold molds built for programs in production today — so a mold adjustment is a machining job on our floor, not a phone call to another company. Molding, assembly and electrical testing and validation share one roof, which is how prototype samples leave in as fast as 3 working days and production runs ship 14 working days after approval.

Factory audits are welcome — in person or by live video walk-through of the molding area, assembly lines and inspection benches, arranged in advance. We build and inspect to IPC/WHMA-A-620 Class 3 workmanship criteria under an ISO 9001 certified quality management system, and every overmolded harness passes 100% continuity and pinout testing before it is packed.

What we control, and what goes wrong when nobody does.

Insert movement

Connector shifting during injection causes pin misalignment. Controlled by holder design and injection sequence.

Flash at the parting line

Controlled by tool fit, clamp tonnage and shot parameters; checked at first-piece and in process.

Short shots at the cable exit

Usually a gating or venting issue. Resolved at mold concept stage rather than by raising temperature.

Delamination from the jacket

A material compatibility and surface-preparation issue — confirmed before tooling, not after.

Sink marks on thick sections

Controlled by wall-thickness uniformity in the mold concept, not by packing pressure alone.

Stress cracking at the strain relief

Geometry and radius design, validated by bend and pull checks before release.

Options available.

• Exit geometry — straight, right-angle or custom exit angle
• Color — Pantone or sample match
• Identification — molded-in logo or part number
• Strain control — integrated strain relief and bend limiter
• Sealing — sealed boots and gasket paths to IP65 / IP67 / IP68 / IP69K design targets
• Low-pressure molding — for delicate inserts and thin-wall connectors
• Integration — overmold-to-panel or overmold-to-bracket geometry

Typical applications run from automation and robotics to medical devices and automotive and EV builds — anywhere a molded boot has to survive flex, fluid or washdown. For reference builds, browse our custom wire harnesses and M8 and M12 circular cables.