An experimental study of small-scale square three-point bend A-36 steel specimens with deep@ intermediate and shallow flaws was conducted to confirm the crack depth to specimen width ratio (a/W) effect for small specimens and to begin to examine the structural significance of shallow-flaw test results. This report discusses the significance that the higher fracture toughness exhibited by shallow-flawed specimens has on fitness-for-service evaluations of existing structures. The research work reported herein was sponsored by the American Iron and Steel Institute and the Subcommittee on Failure Modes of Components of the Pressure Vessel Research Council