An issue with the stranded wire is that the individual strands can be quite fine, so if you attempt to tighten a screw down on them (for instance in a connector block), the wires can break leaving a weak connection.

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One potential solution is to solder the ends of the wire, but this is time consuming, expensive and can result in burns to the wire insulation and your skin!

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There were other needs; for instance, wires may need to be joined but the joint has to be detachable for maintenance or repair. Electric motors often have terminal posts for connecting wires to – this requires the end of the wire to finish in a ring.

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This all drove the development of a wide range of fittings that are attached by squashing them (in a precise way) onto the end of the wire. 

These fittings have a fairly wide range of names including crimps, crimp connectors, crimp terminals, terminals or lugs. We will call them crimp connectors.

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In the UK, crimp connectors are used mainly in control panels, car accessory fitting and the like – This is because the majority of domestic and commercial electrical installation work is done using solid core wire (Flat twin and earth wire) which can be connected straight into terminals.

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It’s rather different on the continent. There they use multi-strand wire on far more applications, so have a much greater need to use crimp connectors to terminate the wiring.

So let’s now take a look at the different types of crimp connectors commonly used.