Cable Assembly Design Criteria

Often times, minor details can substantially increase the cost and the complexity of a cable assembly, and may not be necessary.

Here are some ways to keep quality high and hold costs down:

• Supply full-scale drawings.
• Give precise dimensions with loose tolerances. Keep tight tolerances to a minimum use three decimal places with a tolerance of +/- .030 inches.
• Specify all dimensions from the connector reference plane.
• Avoid direct marking; use shrink tube markers or self-laminating labels.
• Specify center and outer conductor material if there are any special requirements.
• Design bend radii as large as possible.
• Specify the cable or connector, but state "or equivalent" if possible. Different manufacturers often make identical parts but with wide variance in cost.
• Specify electrical properties only across desired frequency ranges, as over-testing can be expensive.
• Avoid female terminations since the connector may require special orientation.

See our blog post to learn how we turned a napkin sketch into a production ready cable assembly.

At a Glance: Design Criteria

• Thoughtful cable assembly design can reduce manufacturing cost and complexity without sacrificing performance, reliability, or quality.
• Full-scale drawings, realistic tolerances, proper bend radius specifications, and clear dimensional references help streamline production and minimize errors.
• Specifying only the required electrical and mechanical characteristics avoids unnecessary testing, special handling, and higher component costs.

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Cable Assembly Process

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Frequently Asked Questions

Quick Links

• What information should be included when designing a custom cable assembly?
• Why are cable assembly tolerances important?
• How can specifying components impact cable assembly costs?
• Why should electrical testing requirements be carefully defined?
• What design practices help simplify cable assembly manufacturing?

What information should be included when designing a custom cable assembly?

A complete cable assembly design package should include full-scale drawings, connector details, cable specifications, dimensions, tolerances, labeling requirements, and any special electrical or material requirements. Providing clear documentation reduces ambiguity during manufacturing and helps prevent costly revisions or delays. Dimensions should be referenced consistently, preferably from the connector reference plane, to improve accuracy and repeatability. The more complete the design information, the more efficiently the assembly can move into production.

Why are cable assembly tolerances important?

Tolerances directly affect manufacturing complexity, inspection requirements, and overall cost. Tight tolerances should be applied only where necessary for proper fit, function, or performance. Overly restrictive dimensional requirements can increase production time and rejection rates without providing a meaningful benefit to the finished assembly. Using practical tolerances helps maintain quality while keeping manufacturing costs under control.

How can specifying components impact cable assembly costs?

Connector and cable selections can significantly influence material costs and lead times. When acceptable for the application, specifying a particular cable or connector with an "or equivalent" designation allows manufacturers greater flexibility to source comparable components from different suppliers. This flexibility can reduce procurement costs and improve availability. It can also help minimize the impact of supply chain disruptions without affecting assembly performance.

Why should electrical testing requirements be carefully defined?

Testing beyond the frequencies or performance levels required by the application can add unnecessary cost to a project. Specifying electrical performance only across the desired frequency range ensures that testing remains aligned with actual operating requirements. This approach helps avoid excessive validation expenses while still confirming assembly performance. Clearly defined test criteria also improve consistency between design expectations and production verification.

What design practices help simplify cable assembly manufacturing?

Several design choices can make cable assemblies easier and more cost-effective to build. These include using larger bend radii, minimizing tight tolerances, avoiding direct cable marking when labels or shrink tube markers are acceptable, and reducing the need for specialized connector orientations. Simplified designs typically require less labor, fewer custom processes, and less rework during production. As a result, manufacturers can deliver assemblies more efficiently while maintaining quality standards.

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