... steel 2.Surface Treatment:Zinc,Chrome,Nickel Plating 3.Wire dia:from 0.01-3.0mm Remote control battery ... spring with double coil(Samples Welcomed ) 1.Material:carbon steel,piano steel,SUS,plated steel 2. ... -gel shell made of mid-temperature wax materials;2) Two lines of lost-wax casting of carbon ... , meet the RoHS standards (SGS test Remote control battery spring with double coil