FINE GAUGE Wire

We call fine gauge wires those that, once they reach the drawing limit allowed by the rod (around 0.90 mm), are annealed to recover their ductility so drawing can continue down to finer sizes. The material is given a chemical surface treatment that deposits a microcrystalline layer of zinc phosphate. That layer is an excellent lubricant carrier during drawing: it sharply reduces friction and die wear, and adds a base level of corrosion protection.

This further reduction raises the hardness slightly. If needed, the material can go through a second annealing to gain ductility once again.