Cable Assembly: Types, Manufacturing Process & Custom Solutions for OEM Applications

A comprehensive engineering guide covering cable assembly fundamentals, types, manufacturing processes, selection criteria, and industry applications.

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What Is a Cable Assembly?

A cable assembly is a group of wires or cables enclosed within a protective outer sheath, terminated with connectors at one or both ends, designed to transmit electrical power, signals, or data between components or systems. The protective covering—typically made from thermoplastic, rubber, or vinyl—shields the internal conductors from environmental hazards like heat, moisture, abrasion, and electromagnetic interference.

As an engineer who has specified hundreds of cable assemblies for industrial control systems, I can tell you that cable assembly quality directly impacts system reliability. The right cable assembly simplifies installation, protects your investment, and prevents costly failures in the field.

Cable assemblies differ from loose wire in several important ways:

Characteristic	Cable Assembly	Loose Wire
Organization	Pre-bundled, routed, terminated	Individual conductors
Protection	Outer sheath shields all conductors	Individual insulation only
Installation	Plug-and-play connectivity	Requires field termination
Reliability	Factory-tested, consistent quality	Depends on field workmanship
Cost	Higher initial, lower total cost	Lower initial, higher labor

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Types of Cable Assemblies

Cable assemblies come in numerous configurations, each optimized for specific applications.

Coaxial Cable Assemblies

Coaxial cables consist of a center conductor, dielectric insulation, metallic shield, and outer jacket. The concentric design provides excellent high-frequency performance with minimal signal loss.

Coax Type	Impedance	Typical Applications
RG-58	50Ω	Radio communications, instrumentation
RG-59	75Ω	CCTV, analog video
RG-6	75Ω	Cable TV, satellite, broadband
RG-174	50Ω	GPS antennas, portable equipment
LMR-400	50Ω	Wireless base stations, long runs

Common Coaxial Connectors:

• BNC – Bayonet lock, test equipment, video
• SMA – Threaded, RF equipment up to 18 GHz
• N-Type – Threaded, outdoor RF, up to 11 GHz
• F-Type – Consumer video, cable TV

Multi-Conductor Cable Assemblies

These assemblies contain multiple insulated conductors within a common jacket. They’re the workhorses of industrial control and power distribution.

Configuration	Best For
Unshielded	Non-sensitive power and control
Foil Shielded	Basic EMI protection
Braid Shielded	High EMI environments
Individually Shielded	Sensitive analog signals

Ribbon/Flat Cable Assemblies

Ribbon cables arrange multiple conductors in a flat, parallel configuration. They’re ideal for applications requiring:

• Mass termination (IDC connectors)
• Compact internal routing
• High conductor density
• Organized, repeatable cable management

Common Applications:

• Computer internal connections (IDE, floppy)
• Printer interfaces
• Industrial control panel wiring
• PCB-to-PCB connections

Fiber Optic Cable Assemblies

Fiber optic assemblies transmit data as light pulses through glass or plastic fibers. They offer immunity to electromagnetic interference and support extremely high bandwidth.

Fiber Type	Core Size	Data Rate	Distance
Single-mode	9µm	100+ Gbps	Up to 100 km
Multi-mode OM3	50µm	10 Gbps	Up to 300m
Multi-mode OM4	50µm	100 Gbps	Up to 150m
Plastic Optical (POF)	1mm	100 Mbps	Up to 100m

Power Cable Assemblies

Power cables deliver electrical energy from sources to loads. They range from low-voltage control power to high-voltage distribution.

Voltage Class	Conductor Range	Applications
Extra-low (< 50V)	28-14 AWG	Control circuits, sensors
Low (50-600V)	18-4/0 AWG	Equipment power, motors
Medium (600V-35kV)	8-500 MCM	Industrial distribution

Custom/Specialty Cable Assemblies

When standard products don’t fit, custom assemblies fill the gap:

• Overmolded assemblies – Strain relief and environmental sealing
• Hybrid assemblies – Power + signal + fiber in one cable
• Retractable assemblies – Coiled cables for tools, phones
• High-flex assemblies – Robotic arms, drag chains
• Waterproof assemblies – Marine, outdoor, washdown

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Cable Assembly Manufacturing Process

Stage 1: Engineering and Design

Every quality cable assembly starts with proper engineering. The design phase establishes:

Electrical Requirements:

• Number and gauge of conductors
• Voltage and current ratings
• Signal frequency and impedance (if applicable)
• Shielding requirements

Mechanical Requirements:

• Overall length and tolerances
• Connector types and orientations
• Bend radius constraints
• Strain relief specifications

Environmental Requirements:

• Operating temperature range
• Moisture and chemical exposure
• UV resistance
• Flame rating (UL, CSA requirements)

Documentation Deliverables:

Document	Purpose
Cable Assembly Drawing	Master specification with dimensions
Bill of Materials	Complete parts list for procurement
Test Specification	Inspection and test requirements
Work Instructions	Step-by-step assembly procedures

Stage 2: Cable and Component Preparation

Cable Cutting: Precision cutting equipment ensures accurate lengths. Typical tolerances:

• Standard applications: ±6mm (±0.25″)
• Critical applications: ±3mm (±0.125″)

Cable Stripping: Automated stripping machines remove outer jacket and conductor insulation:

• Jacket strip length – Exposes inner conductors for termination
• Conductor strip length – Matches terminal barrel dimensions
• Shield preparation – Combing, trimming, or pigtailing as specified

Shield Processing:

Shield Type	Processing Method
Braided	Comb back, trim to length, apply drain wire
Foil	Fold back or trim, use drain wire
Spiral	Unwind, trim, terminate to connector shell
Combination	Process each layer per specification

Stage 3: Termination

Terminal application is the most critical step in cable assembly manufacturing.

Crimping: The most common termination method. Critical parameters:

Parameter	Specification Source	Verification Method
Crimp height	Terminal manufacturer	Micrometer measurement
Crimp width	Terminal manufacturer	Visual or measurement
Pull force	IPC/WHMA-A-620 or customer	Pull test equipment
Insulation support	IPC/WHMA-A-620	Visual inspection

Soldering: Used for certain terminals, shield terminations, and PCB connections.

Parameter	Acceptable	Defective
Wetting	Complete, smooth fillet	Incomplete, dewetted
Surface	Smooth, shiny (leaded)	Grainy, dull
Flux Residue	Clean or per specification	Excessive, corrosive type

Insulation Displacement (IDC): Ribbon cables commonly use IDC termination where contacts pierce insulation to contact conductors.

Ultrasonic Welding: Preferred for aluminum conductors and high-reliability splicing.

Stage 4: Assembly and Protection

Connector Assembly:

• Insert terminals into housing (proper seating, orientation)
• Install secondary locks and seals
• Apply backshells and strain relief
• Attach cable clamps or tie-downs

Protective Covering:

Material	Protection Level	Flexibility	Cost
Spiral Wrap	Abrasion, bundling	High	Low
Braided Sleeve	Abrasion, heat	Medium-High	Medium
Heat Shrink	Moisture, strain relief	Low	Low
Corrugated Conduit	Crushing, abrasion	Medium	Medium
Overmolding	Environmental, strain	Low	High

Labeling: Per specification, labels identify:

• Assembly part number
• Wire/pin designations
• Manufacturer and date code
• Regulatory markings (UL, CSA, CE)

Stage 5: Testing and Inspection

Standard Electrical Tests:

Test	Purpose	Typical Specification
Continuity	Verify connections	< 1Ω per circuit
Isolation	Check for shorts	> 100 MΩ between circuits
Hi-Pot	Insulation integrity	1000-1500V AC, 1 minute
Contact Resistance	Terminal connection quality	< 10 mΩ

Inspection Points:

Checkpoint	What to Verify
Incoming Materials	Correct part numbers, no damage
Strip Quality	Length, concentricity, no nicks
Crimp Quality	Height, position, insulation grip
Assembly	Correct routing, secure fit
Cosmetic	No damage, proper labeling

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Selecting the Right Cable Assembly

Step 1: Define Electrical Requirements

Start with the basics:

• How many circuits?
• What voltage and current?
• Is this power, signal, or data?
• What frequencies are involved?

Step 2: Understand the Environment

Environmental factors drive material selection:

Factor	Impact on Selection
Temperature	Insulation/jacket material rating
Moisture	IP rating, sealed connectors
Chemicals	Compatible jacket material
UV Exposure	UV-stabilized materials
Abrasion	Jacket durability, outer protection
Flexing	Flex-rated cable, strain relief
EMI/RFI	Shielding type and coverage

Step 3: Match Mechanical Requirements

Physical constraints matter:

• Available routing space
• Required bend radius
• Connector mounting style
• Length and tolerance
• Weight limitations

Step 4: Consider Regulatory Requirements

Many applications require agency listings:

Marking	Meaning
UL Listed	Meets UL safety standards
CSA Certified	Canadian safety approval
CE Marked	European conformity
RoHS Compliant	Restriction of hazardous substances
REACH Compliant	European chemical regulation

Step 5: Evaluate Total Cost

Consider lifetime costs, not just purchase price:

• Initial cost
• Installation labor
• Reliability/failure rate
• Maintenance requirements
• Downtime cost of failures

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Cable Assembly Applications by Industry

Automotive

Vehicles contain thousands of electrical connections. Cable assemblies are used for:

• Engine wiring (high-temperature materials)
• Body electronics (door modules, lighting)
• Infotainment systems
• Electric vehicle battery systems
• Safety systems (airbags, ABS)

Key Requirements:

• IATF 16949 quality management
• Temperature rating for zone of installation
• Vibration and fluid resistance
• Lightweight materials for fuel economy

Medical Devices

Patient care depends on reliable cable assemblies in:

• Diagnostic imaging (MRI, CT, X-ray)
• Patient monitoring equipment
• Surgical instruments
• Laboratory equipment
• Implantable devices (leads)

Key Requirements:

• ISO 13485 quality management
• Biocompatible materials (USP Class VI)
• Sterilization compatibility
• IPC Class 3 workmanship

Aerospace and Defense

Aircraft and military systems demand the highest reliability:

• Avionics systems
• Flight control wiring
• Weapon systems
• Communication equipment
• Radar and sensor systems

Key Requirements:

• AS9100 quality management
• MIL-SPEC materials and processes
• Weight optimization
• Extreme temperature performance
• Flammability requirements (FAR 25.853)

Industrial Automation

Factory equipment relies on cable assemblies for:

• Motor power and control
• Sensor and instrumentation
• Robotic arm wiring
• Vision system connections
• Network infrastructure

Key Requirements:

• Oil and chemical resistance
• High-flex ratings for moving equipment
• EMI shielding for sensitive signals
• Quick-disconnect for maintenance

Telecommunications

Communications infrastructure uses cable assemblies in:

• Cell tower connections
• Data center cabling
• Broadcast equipment
• Network infrastructure
• Satellite systems

Key Requirements:

• Signal integrity (impedance control)
• Low insertion loss
• Weather resistance for outdoor
• High bandwidth capability

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Working with Custom Cable Assembly Manufacturers

What to Look for in a Supplier

Capabilities:

• Equipment appropriate for your cable types
• Experience with your industry
• Prototype through production capacity
• Testing equipment and capabilities

Quality Systems:

• ISO 9001 minimum
• Industry-specific certifications (IATF, AS9100, ISO 13485)
• IPC/WHMA-A-620 certified personnel
• Documented inspection procedures

Engineering Support:

• Design for manufacturability review
• Material selection guidance
• Testing specification development
• Documentation support

Information to Provide

For accurate quotes and successful execution, provide:

Information	Why It’s Needed
Cable assembly drawing	Complete specification
Bill of materials	Part numbers, quantities
Required certifications	UL, CSA, CE markings
IPC class	Workmanship requirements
Test requirements	Verification criteria
Annual volume	Production planning, pricing
Application description	Helps identify concerns

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Useful Resources and Downloads

Industry Standards:

• IPC/WHMA-A-620 – Cable and Wire Harness Assemblies – shop.ipc.org
• UL 2556 – Wire and Cable Test Methods – ul.com
• SAE J1128 – Low Voltage Primary Cable – sae.org

Design Tools:

• Wire gauge selection calculators
• Voltage drop calculators
• Impedance calculators for RF applications

Connector Manufacturers:

• TE Connectivity – te.com
• Molex – molex.com
• Amphenol – amphenol.com
• Deutsch (TE) – Industrial connectors
• LEMO – High-reliability connectors

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Frequently Asked Questions (FAQs)

What is the difference between a cable and a wire?

A wire is a single conductor (solid or stranded) with insulation. A cable is two or more wires bundled together, often with an overall shield and jacket. For example, a 16 AWG wire is a single conductor; a 4-conductor 16 AWG cable contains four such wires.

How do I determine the right wire gauge for my cable assembly?

Wire gauge selection depends on:

1. Current capacity – Use ampacity tables (NEC, SAE)
2. Voltage drop – Calculate based on length and current
3. Physical requirements – Flexibility, bend radius
4. Temperature – Derate for elevated temperatures

Quick Reference:

AWG	Diameter (mm)	Max Amps (Chassis)	Typical Use
22	0.64	3A	Low-power signals
18	1.02	7A	Control circuits
16	1.29	10A	Light loads
14	1.63	15A	Equipment power
12	2.05	20A	Higher loads
10	2.59	30A	Motors, high current

What IP rating do I need for outdoor cable assemblies?

Exposure Level	Recommended IP Rating
Covered, indirect exposure	IP54
Open weather exposure	IP65
Occasional water jets	IP66
Brief submersion possible	IP67
Continuous submersion	IP68 (specify depth/time)

How long does custom cable assembly production take?

Phase	Typical Duration
Prototype (simple)	1-2 weeks
Prototype (complex)	2-4 weeks
First production run	4-8 weeks
Repeat production	2-4 weeks

Factors extending lead time:

• Custom connectors requiring tooling
• Agency certifications (UL, CSA)
• Long-lead-time components
• High volume requiring ramp-up

Should I buy or make cable assemblies?

Buy from a supplier when:

• Assembly requires specialized equipment
• Volume doesn’t justify equipment investment
• You need certified/listed products
• Quality/reliability is critical

Make in-house when:

• Simple assemblies with common tools
• Prototype quantities
• Frequent design changes during development
• Trade secrets or IP concerns

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Conclusion

Cable assemblies are fundamental components that enable reliable electrical connections across virtually every industry. Whether you’re designing consumer electronics or mission-critical aerospace systems, understanding cable assembly basics helps you specify products that meet your requirements and work effectively with manufacturing partners.

Key takeaways:

• Match cable assembly type to your application requirements
• Consider environmental factors in material selection
• Specify the appropriate quality class for your reliability needs
• Provide complete documentation to your supplier
• Don’t forget regulatory and certification requirements

For more detailed information on specific topics, explore our guides on wire harness assembly, cable harness assembly, and wire harnessing techniques.