We will now switch our focus from posts to wire, and wire amendments. High tensile wire will increase trellis life, reduce maintenance, and has more strength per unit cost then low-tensile wire.  It is suggested by many sources to use 12 1/2 gauge class 3 wire.   12 1/2 gauge wire refers to the thickness of the wire, which has minimum tensile strength 180,000 pounds per square inch.  The class 3 refers to galvanization or the amount of zinc coating on the wire, which will lengthen the effective life of the wire.