Data are provided on the fatigue strength of structural steel I-beams with welded cover plates or stiffening gussets between the web and flange. Sketches of the configurations to which the data apply are presented showing the location of failures. The data are applicable to a wide range of steels and section geometries enduring constant amplitude bending loading for between 10 000 and 100 000 000 cycles. The effects of residual stress, mean stress, joint size, weld geometry and weld grinding are included. Also provided are notes on the effects of cover-plate geometry, and weld types and different attachment methods for gussets.