The development of ultra-high-strength steels (220,000 - 300,000 psi) is reviewed and weld metal developed for use in their fabrication. Six different types of ultra-high-strength weld metal are proposed and the following properties investigated: Transverse and all-weld metal tensile and yield strengths, ductility, hardness, transverse and longitudinal bending properties, toughness as measured by the Charpy V-notch impact, Jominy hardness, grain size determination and Lehigh restrained cracking tests. Most of the tests were made on the weld metal tempered over a wide range of temperatures.