Types of Wire Terminals When Building a Wire Harness

In a previous blog post, we light-heartedly declared ourselves as experts in matchmaking wires with wire terminals. Especially since we have been building wire harness assemblies for over 30 years. We had fun with that blog post and thought it would be helpful to dig deeper into the various Types of Wire Terminals.

Terminals are defined as “a device designed to terminate a conductor that is to be affixed to a post, stud, chassis, another tongue, etc., to establish an electrical connection.” Wire Terminals come in many different shapes and sizes depending on the size of the wire and screw. Several types of terminals include ring, spade, hook, quick-disconnect, bullet, butt terminals and flagged.

Wire terminals are available in insulated and non-insulated. Determining the best fit depends on your project or usage. Wire insulation provides a protective cover serving as a non-conductor. The insulation spares the wire from water and moisture as well as protects against extreme heat or cold. Wire insulation is typically available in vinyl, nylon and heat shrink.  Non-insulated terminals provide much more economic value with its low cost.  Also commonly used when extra protection is unnecessary.

When purchasing various Types of Wire Terminals, make sure that your purchase meets industry standards and project requirements.

Types of Wire Terminals

Ring Terminals

Types of Wire Terminals, Types of Wire Terminals

A ring terminal is a round-ended terminal that easily allows a screw or stud to be attached. Ring terminals also called ring connectors, come in various sizes. It is crucial that the ring terminal is compatible with the wire gauge and stud size. Ring Terminals are either crimped or soldered to the wire. Available in insulated or non-insulated.


Spade Terminals

Types of Wire Terminals, Types of Wire Terminals

Spade Terminals are also called spade connectors or fork terminals due to the shape of the terminal. A spade terminal is available in various sizes depending on the gauge of the wire and stud size. The open-ended spade terminal is convenient to use allowing easy attachment or removal from the screw. Especially for wire harness projects that are tight on space for installation. Available in insulated or non-insulated. 


Hook Terminals

Types of Wire Terminals, Types of Wire Terminals

Similar to the Spade Terminal, Hook Terminals are convenient to use with an open end (imagine a tiny version of Captain Hook). Produced insulated or non-insulated, Hook Terminals offer a simplistic yet durable connection for a variety of projects.


Quick-Disconnect Terminals

Types of Wire Terminals, Types of Wire Terminals

A quick-disconnect terminal provides convenient and reliable use offering an easy connect and disconnect for two wires. Commonly found in auto, industrial and consumer products. Produced insulated or non-insulated, Quick-Disconnect Terminals deliver a stable and durable connection.


Bullet Terminals

Types of Wire Terminals, Types of Wire Terminals

Also called Bullet Connectors, Bullet Terminals make an easy, reliable and secure connection. Simple to disconnect as well. Bullet terminals connect with the male and open ended round female connectors creating a high-quality connection. The connection with bullet terminals helps prevent corrosion and other potentially harmful materials from entering a wire harness.


Butt Terminals

Types of Wire Terminals, Types of Wire Terminals

A Butt Terminal connects or terminates single or multiple wires. Butt Terminals help prevent abrasion and cutting. This extra protection helps keep out moisture, corrosion, and other negative elements. Butt Terminals serve as a simple solution to extend wires due to the ability to mate and connect wires. Simply install each wire on the open end of the connector, then crimp both ends of the terminal to secure the connection. 

Flagged Terminals 

Types of Wire Terminals, Types of Wire Terminals

Flag Terminals also called flag connectors offer a convenient and secure connection. Flag terminals work well in tight spaces as well as when a quick-disconnect is too large. Provides a quick and easy connection and disconnect. Also available in insulated and non-insulated.


Thank you for taking the time to read our blog post on the various Types of Wire Terminals. To continue reading about the Wire Harness Manufacturing process, click on these links: Crimping Wires and Crimping Tools.

To learn more about the wire harness assembly process, please continue reading our weekly “Wire Harness Wednesday” blog series.

Also, click on the following links to learn more on printed circuit boardssoldering circuit boards and soldering safety tips.

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