Wire harness glossary

A quick reference to the terms buyers and engineers encounter when sourcing wire harnesses and cable assemblies.

Construction & process

Crimping — joining a terminal to a wire by compressing it under controlled force; crimp-force monitoring verifies each crimp.

Overmolding — moulding plastic over a connection to seal and strain-relieve it, common on cable assemblies.

Potting — filling a connector or housing with resin to seal against moisture and vibration.

Soldering — joining conductors or terminals with molten filler metal.

Ultrasonic welding — bonding conductors using high-frequency vibration, used for splices.

Braiding / shielding — a woven conductive layer over wires for EMI protection.

Loom / convoluted tubing — protective sleeving that bundles and shields a harness.

Box build — higher-level electromechanical assembly that integrates a harness into an enclosure or product.

Layout & parts

Breakout — the point where wires branch off the main trunk of a harness.

Pigtail — a short length of wire or a connector lead extending from an assembly.

Backshell — a protective housing at the rear of a connector that manages strain relief and shielding.

Strain relief — a feature that stops mechanical load from reaching the electrical termination.

IDC (insulation-displacement connector) — a terminal that cuts through insulation to contact the conductor, avoiding stripping.

Quality & test

IPC/WHMA-A-620 — the industry workmanship standard for cable and wire harness assemblies. See IPC/WHMA-A-620 manufacturers.

Continuity test — verifies each circuit is connected end to end.

Hipot test — applies high voltage to check insulation integrity.

PPAP / first-article — the formal part-approval package required before production, common in automotive (IATF 16949).

Traceability — the ability to trace a finished assembly back to wire and component lots.

Commercial

EAU (estimated annual usage) — expected yearly volume; the biggest driver of unit price after complexity.

NRE (non-recurring engineering) — one-off costs such as tooling and test fixtures, amortised into the piece price.

New to sourcing? Start with how to choose a wire harness manufacturer or browse the directory.