Strength Factors of Steels: A Graphical Method of Correlating Ultimate Tensile Strength, Proof Stress, Brinell and Izod Figures

WHILE considering the specification requirements of various steels, the possibility of graphically correlating the main factors occurred to the writer. At the first attempt, a correlation of ultimate tensile strengths with proof stresses produced, graphically, a sort of hyperbola; at the second attempt, by changing the vertical and horizontal scales, and working to average figures, the graph took the form of a straight line ending in a hyperbolic curve; at the third attempt the graph became a straight line with plotted points not exactly coincidental with the line; the fourth attempt produced the U.T.S./Proof Stress “curve” which is the subject of this paper.