Molex KK connector

In the Molex KK connector, a metal sleeve is secured to the conductor in two places, on the wire and on its insulator. Creating a gas-tight connection between the wire and terminal pin, prohibiting corrosion and the latter forming a strain relief, providing additional resistance to mechanical stress. These usually mate with rows of pins.

Crimping
A Molex KK socket consists of two parts, a housing and metal crimp terminals. The terminals are bought separately. Generally two different sizes are in use, 0.1” for signal connections and 0.156" for power distribution. Use 7/0.2mm multi-strand wire for 0.1” crimp connections, i.e. seven strands of 0.2mm diameter wire inside the insulation.

Using the proper crimping tool makes a good crimp joint easy. A properly crimped joint does not need soldering and is more than strong enough.

Strip about 2 or 3 mm of insulation from the wire. Then with a racheting crimp tool such as the HT-225D. Place the pin into the apropriate crimp tool aperture. Squeeze the crimpers only enough to hold the pin in place. Insert about 3mm of the exposed strands into the pin. Squeeze the crimpers all the way. Release the crimpers, and pull the wire and pin out. The insulation is squeezed by the back of the pin, and the wire is squeezed in the center of the pin. This is to insure good electrical contact and a good hold on the wire. Push the wire and pin into the plastic housing, ensuring that the tab end of the pin goes the correct way into the housing, to lock into the square hole. Using a simpler crimper such as the PA-09 will entail crimping in two steps. First to crimp the conductor then to crimp the insulation.