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Module three: Core Electrician's Tools

Types of Crimping Pliers 


Ratchet  Crimping Pliers

Ratchet crimping pliers are designed to ensure safe, consistent and precise crimping of wires into crimp connectors. Ratchet crimping pliers use a ratchet deadlock system which means that the pliers must be fully closed, before they can be opened again.

They are factory set, which makes sure that the correct pressure is applied to make a safe crimp.

Once the pliers have been fully closed and the crimp is complete, a quick release lever is activated opening the pliers ready for the next crimp.

Ratchet crimping pliers have hardened steel inserts screwed into the jaws of the pliers. These are often referred to as dies.

The crimp shapes in the dies are specially designed to deform the crimp in the best way for secure wire connection so it is important to match the right pliers to the terminal types being used.

In the picture opposite you can see that each of the dies are colour coded – this corresponds to the colour coding for insulated crimps, so selecting the right die is straight forward.

It’s not so straight forward for un-insulated crimps and boot lace ferrules as there is no colour coding, so care has to be taken to match the right die to the size of wire/crimp connector being used

To help, each of the die positions in the jaws are marked with the cross sectional area of the wire that they are designed to work on – so, care has to be taken that the correct size crimp connector is selected and used in the appropriate sized die.

Remember, loose wires are a major cause of electrical fires, so using the right tool for the job is vital.


However, there are more than just Stranded core cable which need to be crimped…

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