Wire Connectors

 Wire Connectors

Wire connectors are fasteners used to make a tight connection between two or more electrical wires. Made of flame-retardant materials, wire connectors prevent wires from contacting other wires or exposed metal surfaces, which could cause a dangerous fault or short circuit. Wire connectors are easy to use, function in a variety of ways for different uses and in most cases don’t require any special tools.


This buying guide will explain the different types of wire connectors, so you can feel confident you’re choosing the right connectors for your project. To learn more about wires and wire gauges, read our Wire Buying Guide.


Factors to Consider


Design – Square-wire spring, grooved interior
Types – Twist-on, twist-on winged, twist-on ground, crimp-on, underground, waterproof, push-in
Colors – Orange, yellow, red, green
Materials – Thermoplastic, ceramic




Wire connector designs make them easy to apply and remove. Most have a thermoplastic, fire-retardant shell over a square-wire spring. When twisted, the spring expands, creating inward pressure that splices the wire together in a tight connection. The tighter the twist, the stronger the splice, but be careful not to over-tighten. Some plastic wire connectors do not have a metal coil center and depend on grooves inside to twist the wires together.


Twist-on Wire Connectors Twist-on Wire Connectors – These connectors don’t require pre-twisting wires, making them ideal for fast, easy connections that don’t slip over time
Twist-on Winged Connector Twist-on Winged Connector – The wings in this design provide extra twisting leverage, for easy installation and removal.
Twist-on Grounding Wire Connectors Twist-on Grounding Wire Connectors – These connectors are designed for making ground connections and bonding non-metallic sheathed cable.
Crimp-on Wire Connectors Crimp-on Wire Connectors – Secured in place with a crimping tool, this type of wire connector serves as a suitable replacement for soldered connectors, although it may not be as strong or reliable as soldered connections.
Underground Wire Connectors Underground Wire Connectors – For use where exposure to rain, moisture, condensation, high-humidity, or a corrosive element is likely, including direct burial applications.
Waterproof Wire Connectors Waterproof Wire Connectors – This design is suited for wire splices exposed to condensation, water, vapors or dust.
Push-in Wire Connectors Push-in Wire Connectors – An alternative to twisting wires together, this type of wire connector has the wires pushed into two to four holes sized for various wire gauges.



Wire connectors are color-coded by size according to the minimum and maximum number of wires they can safely connect. While the colors can vary from manufacturer to manufacturer, the colors typically correspond to the following:


          • Orange – Used for two small wires
          • Yellow – Used for two or three wires
          • Red – Used for three or more wires


The chart below provides some generally accepted guidelines for wire connectors, the wire gauges for which they are appropriate and the number of wires they connect.


Wire connectors chart


Because there are many different sizes of wire connectors, you should check that the connector you are using fits the quantity and gauge of wire you’re connecting together. Download this helpful guide (PDF) to match the gauge and number of wires to the appropriate wire connector.




• The majority of wire connectors are made of a thermoplastic casing with a metal center. Thermoplastic is 
  designed to withstand extreme heat found in high-wattage fixtures and signs.

• Wire connectors used for high-temperature applications can be made of ceramic. These connectors typically 
  do not have a metal core, instead they rely on internally formed concentric grooves to provide the electrical 
  connection when the conductors are inserted and then twisted together.