Article / Standard
IPC/WHMA-A-620E: what it is and why it matters.
The global acceptability standard for cable and wire harness assemblies — written by IPC together with the Wiring Harness Manufacturers Association, and used by aerospace, defence, medical and automotive primes the world over.
Definition
What IPC/WHMA-A-620E actually is.
IPC/WHMA-A-620E is the joint industry standard for the acceptability of cable and wire harness assemblies. It is developed and maintained by IPC — the Association Connecting Electronics Industries — together with the Wiring Harness Manufacturers Association (WHMA). The standard sets out the criteria a finished cable or harness assembly must meet to be considered acceptable for delivery.
In plain English: it is the shared rulebook that buyers and contract manufacturers use to agree on what “good” looks like for a finished harness. Instead of every OEM writing their own workmanship spec from scratch, the industry converged on one document. When a drawing says “build to IPC/WHMA-A-620E Class 2,” both sides know exactly what is being asked.
The standard organises acceptability into three classes — Class 1 (general electronic products), Class 2 (dedicated service electronic products) and Class 3 (high-performance / harsh environment / life-support). Most OEM-grade industrial, EV, bus body and automation harnesses are built to Class 2 with selected Class 3 criteria where the application demands it.
Scope
What the standard covers.
IPC/WHMA-A-620E walks through every process step that goes into building a finished harness and tells the operator and the inspector what each one should look like when done correctly. The headline scope areas:
Process and joint criteria
- Wire preparation — strip length, conductor damage, insulation damage, strand integrity
- Ultrasonic splices — weld compaction, joint integrity and conductor bonding
- Crimping to stamped and machined contacts — bell-mouth, brush, conductor and insulation grip
- Insulation displacement connection (IDC) terminations
- Ultrasonic welding of conductors
- Splices — crimped and ultrasonic-welded — and their insulation
- Connectorization — pin retention, seating, sealing
- Over-molding and potting
- Marking, labelling and identification
- Coatings, encapsulation and protective covers
- Finished assembly criteria — routing, breakouts, bundling, strain relief
What it does not cover
The standard is a workmanship standard — it covers how the harness should be built and inspected, not how it should be designed. Choices like wire gauge, connector series, voltage rating and circuit topology sit with the design owner. IPC/WHMA-A-620E picks up from the drawing and BOM and defines the acceptability rules for executing them.
It also is not a test method standard. It will tell you a crimp must achieve specified mechanical integrity, but the test procedure for verifying that — pull-force fixtures, sampling rates, dielectric test voltages — comes from the customer's test plan and complementary standards.
Why it matters
Why buyers should care.
A wire harness is an integration product. It sits between the connector, the wire, the device and the rest of the vehicle or machine — and when it fails, it fails expensively. IPC/WHMA-A-620E matters for three buyer-side reasons:
1. Shared language
When your incoming inspection team flags a crimp as “not acceptable,” both you and your supplier need to agree on what that means. A-620E gives a reference: the criteria are in print, with photographs and illustrations, and the conversation moves from opinion to evidence.
2. Less ambiguity at sign-off
Without a referenced standard, every new programme starts with a long workmanship spec negotiation. With A-620E cited on the drawing, the workmanship baseline is set on day one and the conversation focuses on the application-specific deltas.
3. QA traceability
For OEMs building to regulated or safety-critical end uses — EV high-voltage circuits, medical equipment, bus body wiring, industrial automation panels — the ability to point at a recognised acceptability standard and demonstrate compliance is a meaningful part of the quality story.
How Magdaus complies
How we build to A-620E.
At Magdaus, A-620E isn't a poster on the wall — it's wired into the seven-step manufacturing flow and into the in-house test bay that every harness passes through before dispatch.
- Wire cutting and stripping on Unistrip-999 — strip length and conductor damage checked against A-620E criteria
- Crimping on HF-2000 — bell-mouth, brush and grip checked, with pull-force sampling per batch
- Ultrasonic splices — weld quality and joint integrity inspected to A-620E acceptability
- Connectorization — pin seating and retention verified before close-out
- Assembly on the routing board — branch lengths, breakouts and strain relief built to drawing
- Marking and labelling — applied and inspected per the standard
- Final inspection — continuity across every conductor, crimp cross section analyser, functional verification per customer test spec
Traceability you can audit
Build records, test results and inspection notes are kept against each batch so that — if a question comes back from your floor six months later — we can pull the record and respond on evidence rather than guesswork.
For customers running their own A-620E audits, our process documentation, equipment list and operator training records are available on request.
FAQ
Buyers usually open with these.
- Acceptability criteria for cable and wire harness assemblies — wire prep, ultrasonic splicing, crimping, IDC, splices, connectorization, over-molding, marking, coatings and finished assembly criteria.
Have a Wiring Harness Requirement?
Let's solve it together.
Whether you are developing a new product, looking for a reliable harness manufacturing partner or facing challenges with your existing harness supplier, talk to the MGTPL team.
- sales@magdaus.com
- Phone
- +91 99869 18158
- Address
- Plot No. 58/A, 4th Phase, Bommasandra Jigani Link Rd, KIADB Industrial Area, Bommasandra Industrial Area, Bommasandra, Bengaluru, Karnataka 560099