Fleet Maintenance Supply Experts

Wiring Safety & Surety: The Electric Terminal


So you’re thinking about taking on a wiring project? Good news. The enhanced performance of any electrical system you’re working on will be well worth the time and effort you invest. 

As you’re probably already aware, electrical work takes special attention and focus. Now’s not the time to take shortcuts, as the hazards of shock and electrocution are ever-present. 

Before you begin, make sure you’re choosing the right components for the job, as well as the highest quality parts available. That includes the electrical terminals

Every electrical component uses terminals to make connections, whether transferring electricity through the system from a power source or when grounding. To function properly, the terminal connection must have a sound mechanical and electrical contact to work effectively and prevent damage to the conductors. 

Since electrical currents and wire sizes vary based on the project, you will need to do some research to find the right one that can handle the electrical load and protect the wires at their connection points. 

While there are a huge number of electric terminal variations, the category can be broken down into some basic subsets:

Ring Terminals 

Ring terminals connect wiring to screws and studs. Different ring sizes will fit the requirements of amperage throughput, as well as the wires being used.  You’ll need to know the size of ring terminals to fit the wires you are using, which is determined by the size of the conducting wire and the placement of the screw or bolt. 

Spade Terminals

Also referred to as spade connectors, forks or split rings, spade terminals are used to connect or terminate a single wire while it is connected to a stud or screw that is being used for an electrical connection.  

Hook Terminals

Similar to the spade terminal, with a hook shape that offers unique benefits in some applications, such as when the terminal has to hang vertically while tightened.

Butt Connectors

Butt connectors (or butt splice connectors) are commonly used to connect or splice two wires together to lengthen, change, or repair an electrical circuit. 

The highest quality are produced from tin plated copper, which provides maximum conductivity and holding strength, and nickel-plated steel, to handle high temperatures -- often up to 900°F. Butt splice connectors are generally found in the wiring systems of automotive, marine, commercial, and industrial applications. 

Production Materials

Vinyl Terminals have a wide opening which allows the wires to slide into the barrel easily. They’re made from tinned plated copper body and tinned copper wire support with a PVC plastic barrel.

An insulation sleeve is used in a closed barrel that will link a wire to an electrical component. Vinyl provides good dielectric strength and supports the wire insulation in the barrel. Keep in mind that this is a lower-cost option. Though the insulation sleeve protects the wires, it does not fully encapsulate the connection. 

Nylon Terminals

Nylon Terminals are insulated with nylon material and offer better performance than vinyl. Nylon terminals are a double-crimp style, meaning you will crimp the wire at the bottom and the top which will provide for a better connection.  

The nylon material is elastic, so they stretch and won’t crack the insulation inside the terminals. It is more flexible than a plastic connector which helps to minimize damage to, or expose the wires when moved, which could lead to electrical failure. Nylon has good dielectric properties, won’t ‘gas out’, and is more resistant to oils and combustible fluids. 

Heat Shrink Terminals 

When a complete seal is important, Heat Shrink Terminals protect against contamination and moisture. 

It is important to make sure you have a good fit and that copper wiring is not exposed. To accomplish this, prepare the wire and insert all copper strands into the terminal barrel.

Then, crimp the terminal before applying heat. You will need to apply heat from a commercial heat gun or paint peeling gun. Products like hair dryers do not have enough BTU to heat the terminal. 

By applying heat, the adhesive material begins to shrink and then melts onto the wire, forming a tight seal and keeping the insulation and wires safely encased. The new seal insulates the wires, making it airtight and resistant to moisture and chemicals. It also prevents strain on the wire connection. Testing the connection is an important last step, so be sure to pull on the wires after sealing to make sure it is secure.  

The seal prevents the wires from being exposed to damaging corrosive liquids such as salt and freshwater, acid, chemicals, as well as to outdoor elements. Heat shrink terminals are perfect for many automotive and marine applications, and industrial applications. 

Crimping Tool

A Crimping Tool is used to crimp the terminal to the wire, producing a secure bond. They are used on a range of wire sizes from 10 to 24 gauge. Before crimping, you must strip the wire no more than 3/8” from the wire end, then insert the exposed wire into the terminal end.

Ready to Wire? Then We’re Ready to Help

We’ll be glad to help you out with a full selection of terminals and terminal assortments, plus expert advice on helping you locate the right solutions for the job. When you’re ready, just reach out to your Dedicated Account Advisor and we’ll get started. Happy wiring!

Follow Us