Curves showing column strength of steel and duralumin tubing
This is a 1929 NACA technical note from the NASA Technical Reports Server, a set of engineering charts for steel and duralumin tubing used as aircraft struts and columns. The pictures are plain graph sheets with black curves plotting allowable load against tube length in inches, with labelled families of curves for different tube diameters and wall thicknesses, and a small cross-section sketch of an oval tube. A designer might borrow the spare, measured chart layout, the nested descending curves and the tidy grid of numbered axes as a reference for technical diagram styling.
