The book describes the results of over 20 years research completed this year at one of the world's premier consumable manufacturers and aimed at improving the properties of MMA electrodes for high quality applications. It examines the influence of some 17 elements and welding variables on the composition, microstructure and mechanical properties of the resulting weld metal. The often complex relationships discovered are sufficient to give a good understanding of the properties of weld metals produced by other arc welding processes.