Torsional Strength of Nickel Steel and Duralumin Tubing as Affected by the Ratio of Diameter to Gage Thickness
This is a 1924 NACA-style engineering report by the National Advisory Committee for Aeronautics on torsional strength of nickel steel and duralumin tubing, written for aircraft structure engineers. The pictures are plain black-and-white line graphs with grid paper, plotting torque against twist in degrees for tube specimens and modulus of rupture against diameter-to-gage ratio, with fitted curves and tabulated specimen data. A designer might take from them only the restrained chart vocabulary of technical plates: labelled axes, tick marks, data points joined by fitted lines, and small specimen tables.
