Small diameter heaters have small diameter terminal pins into which the lead wire is crimped. Generally, this is not a problem because the wattage is not too high and the amperage is very low. But if the application requires higher amperage-carrying ability or resistance to repeated flexing, larger diameter wire must be employed.

When small diameter pins exclude the use of larger gauge wire, the AFX termination is used. A tapered pin is used to accommodate the larger O.D.of the wire and the smaller end is welded onto the terminal pin.

Watt-Flex® Cartridge Heater with AFX Termination

One other benefit of this construction is that the wire is inserted into the termination with the insulation. When a wire is crimped into a terminal pin, that crimp becomes the focus point for any flexing and stress on the wire. But the AFX termination includes the insulation and provides support for the wire with the insulation. It also displaces the focus of the stress to a point that includes insulation.

This is an ideal construction if you have a small diameter heater and the need for higher amperage capacity or protection against finer wire breakage due to flexing or cycling as in a packaging machine.