The codes covering fabrication of virtually all steel structures and pressure vessels require that weldmetal strength equal or exceed base-metal strength. Until recently, however, it was rare that consideration would be given to how much weld-metal strength in excess of base-metal strength was acceptable.There are certain instances, such as when machining of the weld is to be done, or when the weld is to see service in a corrosive environment, that an overly strong or hard weld causes problems.The particular situation of hard welds in corrosive service has caused concern in the petroleum-refining industry and has provided the motivation for the study to be described herein, which was sponsored by the American Petroleum Institute’s Division of Refining, Subcommittee on Corrosion, under the direction of the Task Group on Corrosion Research.