Production of electric discharge chips made from precious metal for a spark plug comprises wire drawing a bloom made from an iridium alloy using a drawing die and rolling to a coarse wire, and cutting the coarse wire to form the chip

摘要

Production of electric discharge chips made from precious metal comprises wire drawing a bloom made from an iridium alloy containing 0.5-35 weight % of another metal component other than iridium using a drawing die and rolling to a coarse wire having a cross-sectional surface of 0.05-1.2 mm2, and cutting the coarse wire to a predetermined length to form an electric discharge chip to fix to at least one free end section of a middle electrode or the opposite-lying section of an earth electrode.