Like anything you do in your business, the right tool for the job and using it properly is critical when crimping terminals.

Bad connections are to blame for many problems, but knowing how to make proper crimped terminals will go a long way toward avoiding issues. Simply twisting wire together, using wire nuts, or wrapping wire around a terminal screw will not do.

Make sure your electrical connections are secure; quality is the key. Cheap crimpers bend and deflect under pressure, leading to offsetting crimps that provide insufficient pressure at the crimp point. A good crimper will create a high quality electrical and mechanical connection between the wire and the barrel of the terminal. Investing in a good set of ratchet crimpers makes an excellent double crimp, and the ratchet action means they won't release until sufficient pressure has been applied.

Terminals and wires come in a variety of sizes. The smaller the gauge number, the higher the electrical load. Use the wire or cable that's correctly sized to match the maximum current that your project needs to handle.    

A properly crimped terminal is neat, allows the free movement of electricity, resistant to moisture, and prevents open and short circuits.

Choosing the correct tool for the job:

  • Standard cutting/stripping/crimping:Standard cutting/stripping/crimper: Great all-in-one option for the entire process that can cut and strip wire, crimp insulated and non-insulated terminals, trim screws, and reform threads.
  • Battery terminal crimper: Offers crimping of battery terminals, lugs and conventional stamped terminals of any thickness
  • Ratcheting crimper: Provides a ratcheting mechanism to ensure a complete crimp cycle, as well as easy double crimping for nylon terminals

Choosing the correct terminal:

  • Is weather or moisture a factor?
  • Does this application involve movement and vibration?
  • Are you connecting different sizes or gauges of wire?
  • Is using a torch or heat gun a concern?
  • Are you connecting multiple wires?

Making the crimp:

  • Cut back any ragged ends of the wire using the cutters built into the appropriate crimping tool.
  • Strip off the insulation from the wire using the reference scale that corresponds to the wire gauge. Cut only through the sheathing and not into the actual wire. Remove only enough insulation to allow the wire to enter fully into the terminal and leave only 1/32" of bare wire visible.
  • Twist the strands together between your thumb and forefinger to bind them tightly together, making it easier to push the wire end into the terminal.
  • Slide a terminal connector onto the end of the wire. Use the crimping pliers to squeeze it onto the wire. Most crimping jaws are color-coded and correspond with the color of the terminal.
  • Tug on the connector to test the integrity of the joint. If there's any movement or the terminal comes off, cut back the wire and start again.
  • If using heat-shrink, slide the heat-shrink back up the wire, so it covers the crimp completely. Then use a heat gun or a torch to shrink it into place. Use only enough heat necessary to shrink it to the wire.

Even if you have all the correct tools and parts, a poor crimp can dramatically reduce the electrical connection's reliability, which in turn may lead to downtime or a potentially dangerous situation.