What’s the Difference Between IPC Class 1, Class 2 and Class 3?

In cable assembly manufacturing, quality standards are important for reliability, safety and long-term performance.

The main industry standard is IPC/WHMA-A-620, often simply referred to as IPC620. This global standard sets out the workmanship requirements for cable and wire harness assemblies. 

This gives manufacturers like us a clear framework for producing consistent, high-quality assemblies, while giving our customers confidence that products will perform reliably in real-world use.

One of the most important parts of IPC620 is its classification system, which groups assemblies based on how critical their performance is. The three IPC classes are:

• Class 1
• Class 2
• Class 3

Each class reflects a different level of reliability and inspection requirements.

In this guide, we’ll look at what IPC620 is, explain the difference between Class 1, Class 2 and Class 3, and explore why these classifications matter when choosing a cable assembly manufacturer.

What is IPC/WHMA-A-620?

IPC/WHMA-A-620 is widely regarded as the industry’s main standard for cable and wire harness assemblies.

It was developed by IPC together with the Wiring Harness Manufacturer’s Association to provide a clear reference point for how cable assemblies should be built, inspected and tested. 

The standard covers several important aspects of cable assembly, including:

• Soldering and crimping quality
• Cable termination methods
• Insulation, sleeving and strain relief
• Workmanship acceptance criteria
• Visual inspection requirements

By setting out these expectations, IPC620 offers a clear framework to work within, helping us maintain consistent quality across different industries and applications.

Quick comparison: IPC Class 1 vs Class 2 vs Class 3

Here’s a quick breakdown of what each class means and what it’s typically used for.

We’ve covered each class in more detail below.

IPC Class 1: General electronic products

Class 1 covers products where functionality is important but long-term durability is not essential.

These assemblies are typically used in consumer or low-risk applications where minor imperfections may be acceptable as long as the product functions properly.

Examples of IPC Class 1 applications include:

• Consumer electronics
• Household appliances
• Basic electrical devices
• Toys or low-cost products

In these cases, the focus on making the product works as intended, rather than achieving the highest level of durability.

Because the performance demands are lower, Class 1 assemblies typically allow a wider tolerance for cosmetic imperfections or minor workmanship variations.

IPC Class 2: Dedicated service electronic products

Class 2 assemblies are used in products that require higher reliability and longer operational life. These products will need to perform consistently over time, but failure is unlikely to create immediate safety risks.

Most professional and commercial electronics fall within this category.

Typical Class 2 applications include:

• Industrial equipment
• Commercial electronics
• Telecommunications equipment
• Business systems and infrastructure

With Class 2, manufacturers focus on connections, crimps and solder joints to make sure they are more robust and durable. This helps to reduce the likelihood of premature failure.

IPC Class 3: High-performance and mission-critical products

Class 3 represents the highest quality and reliability level within the IPC620 specification.

These assemblies are used in mission-critical applications where equipment failure could cause significant operational problems, safety risks or financial loss.

For example:

• Aerospace and aviation systems
• Defence and military equipment
• Medical devices
• Life-support equipment
• Critical infrastructure systems

In Class 3 applications, reliability really matters. The manufacturing and inspection requirements are therefore much stricter, including things like:

• Extremely precise soldering and crimping
• Higher-quality materials
• Enhanced inspection processes
• Tighter workmanship tolerances

Why IPC classifications matter in cable assembly manufacturing

IPC classifications help manufacturers match the quality of a cable assembly to the demands of the product it will be used in. Not every application requires the same level of reliability, so the classification system gives clear guidance on how strict the manufacturing and inspection requirements should be.

Without recognised standards like IPC620, production methods and inspection processes could vary widely between manufacturers. That kind of inconsistency can increase the risk of faults, weak connections and health and safety.

This is especially important in sectors like aerospace, medical technology and military.

How Cablepoint meets IPC620 standards

IPC620 isn’t just a guideline for us, it’s a core part of how cable assemblies are produced.

Our team is IPC trained, and every assembly is built and inspected according to recognised industry standards.

Quality checks take place throughout our manufacturing process, including:

• Using approved materials and components
• Inspecting crimps and solder joints during assembly
• Performing visual inspections against IPC620 criteria
• Electrical and continuity testing before dispatch

This structured approach makes sure every cable assembly meets the level of quality required for its application.

Quality standards beyond IPC620

In addition to IPC classifications, our quality processes are also supported by additional internationally recognised certifications.

These include:

• ISO 9001:2015 – Quality Management Systems. Helps to maintain controlled processes, full traceability and continuous improvement across manufacturing.
• ISO 14001:2015 – Environmental Management Systems. Demonstrates our long-term commitment to responsible manufacturing and sustainable operations.
• UL Approval. Allows us to produce UL-certified cable assemblies that meet safety and performance requirements for North American markets.

Together, these standards form the framework that supports our commitment to product quality and compliance.

Cablepoint: Reliable cable assemblies built to recognised standards

Understanding the difference between IPC Class 1, Class 2 and Class 3 helps businesses choose the right manufacturing standard for their products.

Here at Cablepoint, these standards guide every part of the production process. By working to IPC620 standards and internationally recognised certifications, we produce every cable assembly with precision, consistency and reliability.

For customers across industries – from industrial equipment to defence systems – that means confidence that their cable assemblies are built to perform. 

If you’d like to discuss your next project, our team would be happy to help. Get in touch.