Should You Tin Wires Before Crimping?

On many industrial installations the wires will be pin-crimped before insertion. This reduces the risk of stray strands left out of the terminals. Some crimpers result in a square cross-section on the crimp and these work well with the flats grips on the terminals. You should absolutely NOT tin the wires.

Can you crimp a tinned wire?

standards recommend that tinned wire not be used in crimp terminations, under screws (such as in terminal blocks) or when forming mesh splices. The reasoning behind these standards is that downward pressure from the crimp, screw or splice will break the solder joint.

Do wires have to be tinned?

Tinning must be done on bare wire. If the wire is insulated, strip about 3/4 to 1 inch of insulation from the wire end, using wire strippers. This length gives you enough wire to wrap around screw terminals but not enough so that excess wire will be exposed.