526,347. Alloys. POLLAK. J. E. (Richardson, H. A). March 14, 1939, No. 8125. [Class 82 (i)] Sparking plug electrodes are made from an iron alloy containing 10-30 per cent. of chromium and 1 - 10 per cent. of silicon, particularly 25 per cent. of chromium and 2 per cent. of silicon. The carbon content is preferably below 0.1 per cent.