S = Mc / I Where: S = Tensile tension in psi; M = Bending second in inch-lbs (wl2/8); I = Second of inertia—0.04909 (D4−d4) in inches fourth; c = Radius (D/2) of cylinder in inches; w = Excess weight per inch of cylinder full of h2o; l = Size https://alfredl542iln4.p2blogs.com/profile