The Nicore 55 is a unique "wire-within-a-wire" composite metal cored electrode developed to join or repair a variety of cast irons. The deposit consists of approximately 50.5% iron and 48% nickel, permitting expansion during welding. Thermal stresses are minimized due to the less frequent stops and starts previously associated with covered electrodes. Operating 98% argon/2% oxygen shielding, this wire will produce a 97% deposition efficiency.