Common Connector Types for Cable Assemblies: A Practical Selection Guide

Choosing the right connector is essential for building a reliable cable assembly.

Quick Comparison of Common Connector Types

1. Wire-to-Board Connectors

Wire-to-board connectors connect individual wires or a complete cable harness directly to a printed circuit board. They are commonly used in sensors, lighting equipment, battery products, control modules and communication devices.

A typical connection includes a crimp terminal, plastic housing and PCB-mounted header. When selecting this connector type, check the contact pitch, wire gauge, current capacity, number of circuits and header direction.

The locking structure should match the operating environment. A simple friction lock may work inside stationary equipment, while a stronger latch may be required for products exposed to movement or vibration.

2. Wire-to-Wire Connectors

Wire-to-wire connectors join two cable sections without using a printed circuit board. They are commonly found in appliances, lighting systems, battery cables, machinery and modular equipment.

These connectors make installation and maintenance easier because one section of the harness can be disconnected or replaced independently. Available locking methods include friction locks, snap locks, positive latches and threaded couplings.

For moving or vibrating equipment, choose a secure locking design and sufficient strain relief so that pulling forces are not transferred directly to the terminals.

3. RF Coaxial Connectors

RF coaxial connectors transmit high-frequency signals between antennas, receivers, communication modules and wireless devices. Typical applications include GPS, Wi-Fi, cellular communication, vehicle electronics, IoT devices and industrial monitoring.

The connector should match the coaxial cable’s impedance, frequency range, diameter and shielding construction. Installation space and mating frequency should also be considered, especially when choosing between compact internal connectors and stronger external interfaces.

Incorrect cable stripping, crimping or shielding termination can increase signal loss. For demanding applications, the finished assembly should be tested for continuity, insertion loss and signal stability.

4. Circular Connectors

Circular connectors use a round housing with threaded, bayonet, snap-lock or push-pull coupling. They are widely used in industrial machinery, outdoor equipment, transportation systems, medical devices and communication products.

One circular connector may carry power, signals, data or several circuit types together. Its shell provides mechanical protection, secure mating and clear polarization, while sealed versions can resist dust and moisture.

Before selection, confirm the contact arrangement, shell diameter, panel cutout, cable entry and coupling method. The installation should also leave enough space for technicians to lock and release the connector.

5. M8 and M12 Industrial Connectors

M8 and M12 connectors are commonly used with sensors, actuators, motors, industrial cameras and automation equipment. Their threaded coupling provides a stable connection in environments with vibration and repeated movement.

These connectors are available for power, signal and data transmission. However, connectors with the same thread size may still have different coding, pin arrangements or electrical functions.

When specifying an assembly, confirm the coding, contact number, male or female configuration, pin assignment, shielding, cable material and environmental protection.

6. Sealed Connectors

Sealed connectors are designed for cable assemblies exposed to water, dust, temperature changes and vibration. They are widely used in vehicles, battery systems, agricultural machinery, marine devices and outdoor equipment.

A complete sealed system may include the housing, crimp contacts, wire seals, interface seals, cavity plugs and secondary locks. All components must match the selected wire size and connector design.

Incorrect seals, open cavities or partially inserted terminals can allow moisture to enter. For demanding applications, sealing should be verified on the completed cable assembly.

7. Data Connectors

Data connectors are used in networking, charging, computing and electronic communication systems. They are commonly found in industrial computers, cameras, control panels, test equipment and communication devices.

The external connector shape alone does not determine data speed, charging power or shielding performance. The internal conductors, cable construction and termination method must also support the required specification.

For industrial or outdoor equipment, consider locking, sealing and strain relief. A custom or keyed design may also help prevent users from connecting an unsuitable third-party cable.

8. Terminal Blocks

Terminal blocks connect wires through screws, spring clamps or push-in mechanisms. They are commonly used in control cabinets, power supplies, building automation and industrial electrical systems.

They provide easy field wiring, clear terminal identification and convenient maintenance. Pluggable versions also allow a control module to be removed without disconnecting each wire separately.

Terminal blocks require more space than compact connector housings. In applications with vibration or temperature changes, correct tightening torque and cable strain relief are especially important.

9. Overmolded Connectors

Overmolded connectors use molded material around the cable-to-connector transition to provide sealing, strain relief and mechanical protection. They are often used in outdoor sensors, antenna cables, vehicle wiring, medical equipment and industrial communication products.

A custom overmold can also include grip surfaces, orientation marks, logos and mounting features. However, overmolding usually requires tooling and may not be economical for very small quantities.

The connector housing, cable jacket and molding material must be compatible. Crimping, soldering and shielding should be completed correctly before the molding process begins.

How to Choose the Right Connector

The correct connector should meet the electrical, mechanical and environmental requirements without adding unnecessary cost or complexity.

Electrical Requirements

Confirm the operating voltage and current for every circuit.

Current capacity can be affected by wire gauge, contact material, the number of loaded contacts, operating temperature and connector ventilation.

For power applications, voltage drop and temperature rise should be evaluated on the complete cable assembly.

Signal Requirements

Determine whether the cable carries power, low-level signals, high-speed data or RF signals.

High-speed and RF connections may require controlled impedance, shielding continuity and carefully designed transitions between the cable and connector.

A connector suitable for basic control signals may not provide stable performance for high-frequency communication.

Wire and Cable Compatibility

The connector contact must match both the conductor size and insulation diameter.

Important cable information includes:

• Wire gauge

• Conductor material

• Insulation diameter

• Cable diameter

• Number of conductors

• Shielding construction

• Jacket material

• Minimum bend radius

An incorrect terminal may appear acceptable after crimping but still provide weak pull strength or unstable electrical resistance.

Operating Environment

Consider the actual conditions in which the cable assembly will operate.

Possible conditions include water, condensation, dust, oil, chemicals, sunlight, salt exposure, temperature changes, vibration and repeated movement.

Environmental protection depends on the complete assembly, including the connector, cable entry, seals, backshell and panel mounting.

Mechanical Design

The equipment should provide enough room for connector mating, cable bending, locking mechanisms, strain relief and technician access.

A connector may fit inside a digital design but still be difficult to install on the production line.

The cable routing should also avoid excessive tension, sharp bends and contact with moving or heated components.

Production and Supply

Connector selection also affects manufacturing efficiency and supply stability.

Before approval, check component availability, lead time, minimum order quantity, tooling requirements, terminal packaging and replacement options.

A technically suitable connector may still create production delays if its contacts, seals or assembly tools are difficult to obtain.

Common Connector Selection Mistakes

Selecting by Appearance

Two connectors may look similar while using different contact dimensions, locking structures or materials.

Exact specifications should always be confirmed before production.

Mixing Incompatible Components

Connector housings, contacts, seals and locking parts should be selected as one compatible system.

Similar-looking components are not automatically interchangeable.

Ignoring Crimp Quality

Reliable connector performance depends heavily on terminal crimping.

Incorrect tooling or settings may cause high resistance, weak pull strength or damaged conductors.

Missing Strain Relief

Repeated bending near the connector can break conductors or loosen shielding.

Strain relief should be included in the connector housing, backshell, overmold or cable routing design.

Skipping Prototype Validation

A connector may pass visual inspection but fail during electrical loading, vibration, flexing or environmental testing.

The complete cable assembly should be validated before mass production begins.

Information Needed for a Custom Cable Assembly Quote

Complete technical information helps a cable assembly manufacturer evaluate the project and prepare an accurate quotation.

Useful information includes:

• Connector drawing or specification

• Mating interface

• Wiring diagram or pinout

• Cable type and length

• Wire gauge and color

• Operating voltage and current

• Signal or frequency requirements

• Shielding requirements

• Application environment

• Labeling requirements

• Testing requirements

• Prototype quantity

• Estimated annual demand

When the connector has not yet been selected, application requirements can be provided instead.

The manufacturer can then compare suitable connector types according to electrical performance, cable compatibility, sealing and production needs.

Custom Cable Assembly Solutions from RY

RY provides custom cable assembly and connector solutions for wireless communication, GPS, Wi-Fi, cellular networks, IoT devices, industrial equipment and automotive electronics.

We can manufacture cable assemblies based on your drawings, connector specifications, samples or application requirements. Our team can support connector selection, cable matching, wiring design, shielding, labeling, overmolding and electrical testing.

To receive an accurate quotation, please provide your connector requirements, wiring diagram, cable type, cable length, operating environment, prototype quantity and estimated annual demand.

Learn more about our custom cable and antenna solutions at RY.

Frequently Asked Questions

Can a custom cable assembly be produced from a physical sample?

Yes. A physical sample can be used to identify the connector interface, cable construction, dimensions and wiring arrangement. However, providing the electrical requirements and intended application can help prevent an unsuitable existing design from being repeated.

Can one cable assembly use several different connector types?

Yes. A cable assembly can include different connectors, cable branches, terminals and protective components. The wiring diagram should clearly show each branch length, connector orientation, pin assignment and labeling requirement.

How can cable assembly costs be reduced without affecting reliability?

Cost can often be reduced by simplifying unnecessary cable branches, standardizing wire colors, selecting readily available components and avoiding excessive customization. Cost reduction should not compromise conductor size, contact quality, sealing or required testing.

What should be checked before approving a production sample?

The approved sample should be checked for overall length, branch dimensions, connector orientation, pin assignment, labeling, crimp quality, electrical continuity and appearance. It should also be tested inside the actual equipment whenever possible.

Can RY support both prototypes and volume production?

RY can evaluate projects based on prototype requirements and estimated production demand. Providing both quantities during the quotation stage helps determine suitable components, tooling and manufacturing methods.