Do you twist the wires before wire nut?

Yes, it is best practice to twist electrical wires together using pliers before applying a wire nut, ensuring a secure and permanent mechanical connection. While some modern twist-on wire connectors are technically rated to bite onto straight, parallel wires without pre-twisting, doing so manually with lineman's pliers creates a rock-solid foundation that eliminates guesswork and prevents loose strands from slipping out. Pre-twisting aligns the copper conductors perfectly, allowing the internal metal spring of the wire nut to grab and compress the entire bundle uniformly. This extra step is especially crucial when combining multiple wires or mixing solid and stranded conductors, providing an essential layer of safety and durability against long-term vibration and thermal expansion in electrical junction boxes.