In the electronics industry, crimping is the process in which a wire is permanently fixed to the contact of a connector using mechanical force. Crimps come in many forms and sizes but the principle behind them is the same.
The object of terminating wires is to obtain the strongest mechanical connection with the highest electrical conductivity. Poor mechanical terminations can result in broken wires or intermittent connections. Poor electrical terminations can cause failed or erratic circuit operation, undesirable heat build-up and even fire.
Crimping is accomplished when a contact and wire are inserted in a specially designed tool. The tool is closed, rolling the contact around the wire and crushing it with sufficient force to deform the wire and produce a gas tight connection. During this process, any normal oxidation present on the wire or contact is fractured and displaced providing a clean strong metal to metal connection. The amount of force used during the crimping process will determine the amount of deformation and is gauged by measuring the crimp height. The optimal crimp height is where the connection produces the highest mechanical strength with the highest electrical conductivity.
Crimp height is critical to the long-term performance of the connection and usually needs to be with in +/- .002 inch of the optimal height.
Most connector manufacturers sell tooling for their various products. Tools range from low volume hand tools to semi and fully automatic crimping presses. Hand tools are used for prototype work, very low volume production, and repair work. Most hand tools can accommodate 2 to 4 different contact / wire size combinations. Crimping presses are the preferred method of terminating. Utilizing interchangeable crimping dies that automatically feed the contacts into the tool. The interchangeable dies, called applicators, are calibrated to a specific contact / wire size combination. They provide a high termination rate with excellent crimp height consistency. Using a semi automatic press, a skilled operator can produce 1800 to 3000 terminations per hour, depending on the type of contact and wire. Fully automatic presses can produce as many as 6000 terminations per hour.
