What is the advantage of using a four-sided crimper vs. pliers?

Question

I'm trying to crimp some pins onto 20 AWG wire.

I can either use a tool like this:

Or I can just use pliers, which are obviously cheaper and more readily available. Why should I use the more expensive tool?

Answer 1

It's all about the amount surface area in contact between the two materials.

A pair of pliers will create points of contact on two sides of the wire.

The specialty crimper you linked will provide contact on four sides of the wire.

Having four points of contact provides:

• Better electrical conductance between the pins and the wires
• Better mechanical resistance (aka a friction fit) to pulling and the pins are more likely to stay attached.

Answer 2

The proper crimper will indent the cylindrical body of the contact, leaving the outside diameter unchanged.

Pliers will simply squash the contact, making it oval, and larger than the original diameter in one direction. This may prevent the contact from seating correctly (or at all) in the connector housing. The distorted contact will probably make it impossible to use the contact removal tool to remove the contact from the connector.