Terminology
Cable assembly vs wire harness: what's the difference?
The two terms are often used interchangeably, including by suppliers. The parts they describe are built differently, and that changes how they are specified, priced and inspected.
Cable assembly
A cable assembly is built from cable: several conductors, often with shielding, held inside a single outer jacket. Connectors or terminals are fitted at the ends. The jacket protects the conductors from abrasion, moisture, oil and sunlight, which is why cable assemblies are common where the part is exposed. Examples include external equipment cables, sensor leads, trailer cables and test leads.
Specifying a cable assembly means paying close attention to the cable itself: jacket material, temperature rating, flex life, shielding coverage and outside diameter. Overmolded ends, strain relief and sealing often matter more than the internal wiring.
Wire harness
A wire harness (also wiring harness or wiring loom) is an organized bundle of individual wires and cables, held together with ties, lacing, tape, sleeving or conduit, and laid out to fit a specific space. Harnesses usually have breakouts, branches leaving the main bundle to reach different connectors, and are built on a full-size formboard. Examples include vehicle body harnesses, aircraft and equipment harnesses, and control-cabinet wiring.
A harness is usually protected by the product it is installed in. Specifying one means paying close attention to geometry: branch positions, lengths and tolerances, connector clocking, and how the bundle is secured and routed.
Side by side
| Cable assembly | Wire harness | |
|---|---|---|
| Construction | Conductors inside one jacket | Separate wires and cables bundled together |
| Environment | Often exposed, outside an enclosure | Usually inside the product |
| Geometry | Mostly point to point | Branches and breakouts to many endpoints |
| Key spec items | Cable type, jacket, shielding, overmold, sealing | Layout, lengths, breakouts, bundling, labels |
| Tooling to quote | Molds, test fixture | Formboard, test fixture |
| Workmanship standard | Both are covered by IPC/WHMA-A-620 | |
Examples by industry
| Industry | Typical cable assemblies | Typical wire harnesses |
|---|---|---|
| Aerospace | Test cables, ground support equipment cables, antenna coax | Airframe and engine harnesses, avionics rack wiring |
| Defense | Rugged external cables with circular military connectors | Vehicle and shelter harnesses, equipment wiring |
| Automotive | Sensor leads, charging cables | Body, engine and chassis harnesses |
| Industrial | Sensor and actuator cords, drive cables, robot cables | Control cabinet and machine wiring |
| Medical | Patient-connected leads and probe cables | Internal equipment wiring |
| Transport and cargo | Trailer jumper cables, reefer power leads | Trailer and body harnesses |
For the transport and cargo examples, the sister guide covers trailer wiring harnesses in detail.
How each is inspected
Both are inspected to IPC/WHMA-A-620 criteria where the drawing calls for it, but the emphasis differs. Cable assembly inspection concentrates on the ends: termination quality, shield termination, strain relief, overmold quality and sealing. Harness inspection adds geometry: branch positions and lengths checked against the formboard or drawing, tie and lacing spacing, protection coverage and label placement. Both should be electrically tested; see cable assembly testing.
Where box build fits
A box build, also called systems integration or electromechanical assembly, is a complete or partly complete product: an enclosure with boards, power supplies, switches and the internal wiring between them. Cable assemblies and harnesses are components of a box build. A box build supplier also has to manage board assembly or incoming boards, mechanical fit, and functional testing of the whole unit.
| Cable assembly | Wire harness | Box build | |
|---|---|---|---|
| What is delivered | A cable with terminated ends | A shaped bundle of wires | An assembled unit or product |
| Main workmanship standard | IPC/WHMA-A-620 | IPC/WHMA-A-620 | IPC/WHMA-A-620 for wiring, IPC-A-610 for boards |
| Typical final test | Electrical (continuity, hipot) | Electrical (continuity, hipot) | Electrical plus functional test of the unit |
Parts that are both
Many real parts combine the two. A harness may include jacketed cable runs to external connectors, and a cable assembly may break out into a small harness at one end. Aircraft and vehicle wiring often uses shielded jacketed cables inside a larger harness. In these cases, describe each section on the drawing in the terms that fit it, so both the cable specification and the harness geometry are covered.
Why the distinction matters when you buy
A supplier set up for high-volume cable assemblies with molding capability may be a poor fit for a complex, low-volume harness with forty breakouts, and the reverse is equally true. Naming the part correctly in your RFQ, and supplying the right details for its type, helps the right suppliers quote with confidence. Use the RFQ checklist to put that package together, and the supplier checklist to judge who can build it.
Common questions
Is a wiring harness the same as a wire harness?
Yes. Wire harness, wiring harness, cable harness and wiring loom are used for the same kind of part, although some companies use "cable harness" for a harness built mainly from jacketed cables.
Which is cheaper, a cable assembly or a harness?
Neither by definition. A simple harness can cost less than a complex molded cable assembly. Cost depends on components, labor and tests. See harness cost drivers.
What is a cable harness?
The term is used loosely. Some suppliers mean a harness built from jacketed cables rather than single wires; others use it as a synonym for any harness. If the term appears in a quote, check what the supplier means by it against your drawing.
Does the same supplier build both?
Often, yes. Capability varies, though: overmolding, high-volume automated cable processing and complex formboard work are different skills. Ask for examples similar to your part.
Last reviewed 2026-09-17