IPC/WHMA-A-620 Explained For Purchasing Managers

If you purchase cable or wire harness assemblies, you've likely seen the term IPC/WHMA-A-620 on supplier documentation. But what does it actually mean and why should it matter to your purchasing decisions? Understanding this standard can help you choose better suppliers, reduce quality issues and lower warranty costs over the life of your products.

What is IPC/WHMA-A-620?

IPC/WHMA-A-620 is the internationally recognized standard that defines the requirements and acceptance criteria for cable and wire harness assemblies. It establishes what acceptable workmanship looks like, from crimping and soldering to wire routing, insulation and final inspection.

Rather than being just a collection of photos showing good and bad examples, the standard is a complete system of requirements. As Teresa Rowe, Senior Director of Industry Standards for the Global Electronics Association, explains in Wiring Harness News, users should read the document as a whole because the mandatory requirements begin in Chapter One and apply throughout the standard.

What is the importance of implementing this standard?

For purchasing managers, IPC/WHMA-A-620 provides confidence that suppliers are building products using consistent, proven manufacturing practices. Suppliers that follow the standard aren’t simply checking boxes. They are expected to understand their manufacturing processes, train operators, maintain calibrated tool and verify that every harness meets the required quality level.

This level of consistency reduces the risk of receiving products with hidden defects that could lead to costly failures in the field.

What are the three acceptance classes?

Not every product requires the same level of reliability. IPC/WHMA-A-620 defines three acceptance classes:

Class 1: General consumer products where occasional defects are unlikely to create serious consequences.

Class 2: Products requiring dependable performance, such as many commercial and industrial applications.

Class 3: High-reliability products where failure is unacceptable, including many medical, aerospace, defence, and critical industrial systems.

Some manufacturers choose to build all assemblies to Class 3 requirements to simplify production and deliver higher reliability across every order.

What are the common causes of failure?

Many wiring harness failures aren't caused by poor designs. They often result from inconsistent manufacturing practices, including improper crimping and damaged wire insulation. They can also result from poor solder joints, incorrect wire routing, inadequate strain relief and insufficient inspection or testing. These issues may not be obvious during installation but can lead to intermittent electrical problems, premature equipment failure and expensive warranty claims.

Even small manufacturing defects can have significant consequences once a product is in service. This is especially true in demanding environments where vibration, heat, moisture or constant movement place additional stress on electrical systems. Over time, a weak connection or damaged wire can worsen. The result is unexpected downtime, costly repairs and reduced product reliability.

How does certification help reduce warranty costs?

Working with an IPC/WHMA-A-620-certified manufacturer helps reduce risk because certification emphasizes consistent process control, not just final inspection. According to Teresa Rowe, process control means understanding which parts of the manufacturing process must be monitored to consistently produce acceptable products. It doesn't require complicated systems. It requires disciplined procedures, trained employees and a culture focused on quality.

The result is fewer manufacturing defects, greater product consistency, fewer field failures and lower warranty costs for OEMs. For purchasing managers, choosing a certified manufacturing partner isn't simply about meeting a specification. It's about protecting your supply chain, your reputation and your bottom line.

To learn all about Flux Connectivity’s IPC/WHMA-A-620-certified overmolded cable and wire harness assemblies, please don’t hesitate to give us a call at 1-800-557-FLUX or email us at connect@fluxconnectivity.com. You may also fill out the form on our Contact Us page!