The RJ12 cable is manufactured with four and six wires. The four-wire cable is traditionally used for voice transmission with a telephone service, while the six-wire cable is capable of transmitting both voice and data. The six-wire cable is traditionally used to connect networks. Preparing your RJ12 crimp connector cable whether it is six or four wires requires the same steps.
Strip the end of the telephone wire of the plastic outer coating using the modular crimp tool's blade section. The length will range from an eighth to a quarter of an inch.
Strip the colour wires, one at a time, using the modular crimp tool. To keep from breaking the fine wires, carefully apply pressure when pulling the plastic coating off of the wire.
Place each wire into the modular plug matching the colours. Push the wire as far as it will go -- be careful to not break the fine wires. Repeat for each colour.
Crimp the modular plug using the crimping tool. Do not squeeze too hard to keep from breaking the plug.
Plug your RJ12 connector into the telephone jack and telephone. Or plug the RJ12 six wire into the modem of your computer and other network modules.
You may choose to use a wire stripping tool rather than the blade section of the crimping tool. Wire stripping tools are made to fit different size and type cabling and telephone lines.
Applying too much pressure when crimping the RJ12 connector to the cable will break the plastic.