Lugs

A lug is a very simple type of terminal. Above all, it is specifically designed to be very effective at creating a minimal amount of resistance in it’s connection.  This is usually between the cable and the post of the battery or screw terminal of the device to which it is being connected.

It is important to note that lugs are very specific in the following ways:

1. The choice of lug manufacturer and lug model/part number dictates the exact tool that must be used when crimping on the lug in order to provide a perfect connection. This is a precise mechanical process.  In other words, tolerances count – a lot.

2. The lug metallurgy determines its effectiveness in all aspects of the connection. Bad/inconsistent metallurgy or manufacturing allowing high variation in production will result in failed connections.  Above all, the higher the current, the worse the connection will perform.

3. When specifying a lug, you need to specify the AWG Gauge of wire it is for, and the diameter of the bolt that the hole in the lug will be used with. Common post or hole sizes in marine lugs are #10, 1/4″, 5/16″ and 3/8″.