Blue Crimper Assorted High Quality Crimp Spade Terminal Crimping Tool

Crimper is a device which is used to make solderless electrical connection. Crimp connectors are typically used to terminate stranded wire. The benefits of crimping over soldering and wire wrapping include:

A well-engineered and well-executed crimp is designed to be gas-tight, which prevents oxygen and moisture from reaching the metals (which are often different metals) and causing corrosion
Because no alloy is used (as in solder) the joint is mechanically stronger
Crimped connections can be used for cables of both small and large cross-sections, whereas only small cross-section wires can be used with wire wrap
Crimping is normally performed by first inserting the terminal into the crimp tool. The terminal must be placed into the appropriately sized crimp barrel. The wire is then inserted into the terminal with the end of the wire flush with the exit of the terminal to maximize cross-sectional contact. Finally, the handles of the crimp tool are used to compress and reshape the terminal until it is cold-welded onto the wire.

The resulting connection may appear loose at the edges of the terminal, but this is desirable so as to not have sharp edges that could cut the outer strands of the wire. If executed properly, the middle of the crimp will be swaged or cold-formed.