Wire Harness vs Cable Assembly: Types, Materials & Manufacturing

Why I Added Cable Assembly to Our Services

Five years ago, a customer asked me: "Can you build the entire product, not just the PCB?"

Their device needed a main board, three cable assemblies, and a wiring harness connecting everything. They were managing four different vendors: us for PCBs, a cable house in Taiwan, a harness shop in Mexico, and a local integrator to put it all together.

Four vendors. Four quality standards. Four points of failure. Four invoices to track.

That conversation led us to expand into cable assembly and wire harness manufacturing. Today, we build complete systems—PCBs, cables, harnesses, and box builds—all under one roof.

This guide shares everything I've learned about cable assemblies and wire harnesses, so you can make informed decisions for your project.

Wire Harness vs Cable Assembly: What's the Difference?

People use these terms interchangeably, but they're different products for different purposes.

Simple Rule of Thumb

**Hommer's Shortcut**: If you can see the individual wires when it's finished, it's probably a harness. If it looks like one thick cable, it's an assembly.

The 8 Main Types of Wire Harnesses & Cable Assemblies

Type 1: Automotive Wire Harnesses

The most complex harnesses in existence. A modern car contains 40+ kg of wiring—thousands of individual circuits connecting everything from headlights to seat heaters.

Characteristics: - Extreme length (up to 5km of wire per vehicle) - Multiple connector types in single harness - Temperature range: -40°C to +125°C - Vibration and moisture resistant - Must meet IATF 16949 requirements

Key applications: - Engine compartment - Body wiring (doors, roof, trunk) - Dashboard/instrument cluster - Infotainment systems

Our automotive wire harness production meets IATF 16949 standards.

Type 2: Industrial Control Cable Assemblies

Heavy-duty assemblies for factory automation, machinery, and industrial equipment.

Characteristics: - High current capacity (often 10-100A) - Oil and chemical resistance - EMI shielding for sensitive signals - IP67/IP68 connector ratings - Long service life (10+ years)

Common configurations:

See our industrial cable assembly capabilities.

Type 3: Medical Device Cable Assemblies

The highest precision segment. Patient safety and regulatory compliance drive everything.

Characteristics: - Biocompatible materials (for patient contact) - Sterilization compatible (EtO, autoclave) - Ultra-fine wire (30-40 AWG common) - ISO 13485 manufacturing - 100% electrical testing

Critical requirements:

Our medical device cable production follows ISO 13485 requirements.

Type 4: Robotics & Motion Control Harnesses

Designed for continuous flexing—the nemesis of cable longevity.

Characteristics: - High flex life (10+ million cycles) - Torsion-resistant conductors - Drag chain compatible - Compact bend radius - Quick-disconnect connectors

Flex Life Ratings:

**Hommer's Experience**: Regular stranded wire fails at about 1 million flex cycles. True robotic-grade cable survives 10-20 million. The price difference is 3-4x, but the alternative is downtime. Always specify flex rating for any moving application.

Type 5: Power Distribution Harnesses

High-current harnesses for power electronics, battery systems, and distribution panels.

Characteristics: - Heavy gauge wire (4 AWG to 4/0) - High-ampacity terminals - Arc-flash considerations - Color coding per NEC/IEC - Often copper bus bar integration

Current Carrying Capacity (at 75°C):

Type 6: Coaxial & RF Cable Assemblies

Precision assemblies for high-frequency signal transmission.

Characteristics: - Controlled impedance (50Ω or 75Ω) - Low insertion loss - High shielding effectiveness - Phase-stable designs available - Precision connectors (SMA, N-type, BNC)

Common Types:

For RF applications, we often integrate coax assemblies with our RF PCB manufacturing.

Type 7: Ribbon Cable Assemblies

Flat, organized cables for internal connections—especially common in electronics.

Characteristics: - High conductor count in compact space - IDC (insulation displacement) termination - Easy mass termination - Limited flexibility - Cost-effective for high pin count

Applications: - Computer internal connections - Test equipment - Industrial I/O - LED displays

Standard Pitches: - 2.54mm (0.1") - Most common, IDC compatible - 1.27mm (0.05") - High density - 1.0mm - Ultra-high density

Type 8: Custom Overmolded Assemblies

Premium assemblies with molded strain relief, waterproofing, or branded enclosures.

Characteristics: - IP67/IP68 sealing possible - Integrated strain relief - Custom shapes and colors - Brand logo embedding - Higher tooling cost

When to Overmold: - Consumer products (aesthetics + durability) - Outdoor equipment (waterproofing) - Medical devices (cleanability) - High-volume production (unit cost amortizes tooling)

Tooling Costs: | Complexity | Typical Tooling | Volume to Amortize | |------------|-----------------|-------------------| | Simple cylindrical | $2,000-5,000 | 1,000+ units | | Medium complexity | $5,000-15,000 | 5,000+ units | | Complex multi-part | $15,000-40,000 | 20,000+ units |

The Manufacturing Process

Step 1: Design & Engineering

Everything starts with your requirements: - Electrical specifications (voltage, current, signal type) - Environmental conditions (temperature, moisture, flex) - Mechanical constraints (length, bend radius, connector locations) - Regulatory requirements (UL, CSA, medical, automotive)

We create detailed drawings showing: - Wire routing - Connector pinouts - Splice locations - Labeling requirements - Test specifications

Step 2: Wire Cutting & Stripping

Automated equipment cuts wires to exact lengths and strips insulation from the ends.

Key parameters: | Parameter | Typical Tolerance | |-----------|------------------| | Cut length | ±1mm | | Strip length | ±0.3mm | | Insulation nick | Not allowed |

Step 3: Crimping & Termination

Terminals are attached to wire ends using precision crimping.

Critical crimping metrics: - Pull force (destructive test) - Crimp height (go/no-go gauge) - Cross-section analysis (sample inspection)

**Hommer's Quality Note**: We monitor crimp force on every terminal. A statistical deviation triggers immediate investigation. Bad crimps are the #1 cause of field failures.

Step 4: Connector Assembly

Terminated wires are inserted into connector housings.

Common verification: - Retention force test - Visual inspection - Pinout verification

Step 5: Bundling & Routing

Wires are bundled using: - Cable ties (nylon, metal) - Braided sleeving - Corrugated tubing - Heat shrink - Tape wrapping

Step 6: Testing

Every assembly undergoes electrical testing:

We use 100% automated testing on production runs—no sampling.

Material Selection Guide

Wire Types

Insulation Materials

Jacket Materials

Quality Standards

IPC/WHMA-A-620

The industry standard for cable and wire harness assemblies. Defines: - Workmanship criteria - Acceptance requirements - Testing protocols

Classes: | Class | Description | Examples | |-------|-------------|----------| | Class 1 | General electronics | Consumer, non-critical | | Class 2 | Dedicated service | Industrial, commercial | | Class 3 | High performance | Military, medical, aerospace |

Our harness production meets Class 2 and Class 3 standards depending on application.

UL Recognition

For products sold in North America: - UL 758 (Appliance wiring material) - UL 2238 (Wire harnesses) - UL 62368-1 (IT/AV equipment)

Automotive Standards

• USCAR specifications
• SAE J1128 (Primary wire)
• LV112/LV124 (German OEM specs)

Cost Factors

What Drives Cable Assembly Cost?

Cost Reduction Tips

1. **Standardize connectors** across products
2. **Use common wire colors** (reduces inventory)
3. **Design for automation** where possible
4. **Specify appropriate class** (don't over-specify)
5. **Bundle orders** for volume pricing

Common Mistakes to Avoid

Mistake 1: Wrong Wire Gauge for Current

Undersized wire = heat = fire risk. Always calculate current-carrying requirements.

Mistake 2: Ignoring Bend Radius

Tight bends damage wire over time. Minimum bend radius = 4x cable diameter (typical).

Mistake 3: Incompatible Materials

Some plastics react with each other. PVC next to silicone can cause cracking.

Mistake 4: No Strain Relief

Without strain relief, flex stress concentrates at the connector. Failures guaranteed.

Mistake 5: Under-specifying Flex Life

If it moves, specify flex requirements. "It just needs to bend a little" isn't a spec.

FAQ

What's the lead time for custom cable assemblies?

• Prototypes: 1-2 weeks
• Production (simple): 2-3 weeks
• Production (complex): 3-4 weeks

What's the minimum order quantity?

We have no MOQ for prototypes. Production runs typically start at 50-100 pieces for cost efficiency.

Can you match an existing assembly?

Yes. Send us a sample and we'll reverse-engineer it. We can also improve materials or construction if needed.

Do you provide design assistance?

Absolutely. Send us your requirements and we'll propose a design. We work with incomplete specs all the time.

What testing do you perform?

100% continuity and isolation testing on all assemblies. Hi-pot and pull testing based on requirements or customer request.

Conclusion: The Integration Advantage

The best cable assembly is the one you don't have to manage separately.

When we build your PCBs, cable assemblies, and wire harnesses together, you get: - Single source - One vendor, one quote, one shipment - Integrated testing - We test the complete system - Design coherence - PCB and cable designed together - Simplified logistics - Everything arrives ready to integrate

Ready to discuss your cable assembly needs? Contact us for a consultation, or explore our complete cable assembly services.

Related Reading

Wire harnesses and cable assemblies often integrate with PCBs and other electronic systems. These guides may help:

• **[PCB Materials Guide: FR4, Aluminum & Flex](/blog/pcb-materials-comparison)** – When integrating harnesses with PCBs, material selection affects thermal and mechanical compatibility.
• **[HDI vs Standard Multilayer PCB](/blog/hdi-vs-standard-multilayer-pcb)** – For compact designs where cables connect to dense PCBs, understanding HDI tradeoffs is essential.
• **[Turnkey vs Consignment PCBA](/blog/turnkey-vs-consignment-pcba)** – Single-source manufacturing for PCBs and cable assemblies simplifies your supply chain significantly.

References

1. [IPC/WHMA-A-620](https://www.ipc.org/) - Requirements and Acceptance for Cable and Wire Harness Assemblies
2. [SAE J1128](https://www.sae.org/) - Low-Voltage Primary Cable
3. [UL 2238](https://www.ul.com/) - Cable Assemblies and Wire Harnesses

*Written by Hommer Zhao, founder of PCB Portugal. Our wire harness facility in Shijiazhuang has been serving automotive, industrial, and medical customers since 2010. Last updated: December 2024.*