Structural engineers occasionally need to determine the section properties of steel shapes not found in the current edition of the Handbook of Steel Construction (CISC 2000). The following pages provide the formulas for calculating the torsional section properties of structural steel shapes.

The section properties considered are the St. Venant torsional constant, J, the warping torsional constant, Cw, the shear centre location, yO , and the monosymmetry constant, β x .

Although not a torsional property, the shear constant, CRT , is also included for hollow structural sections (HSS), as it is not easily found in the literature.

Some of the formulas given herein are less complex than those used in developing the

Handbook and the Structural Section Tables (CISC 1997). Effects such as flange-to-web fillet radii, fillet welds, and sloped (tapered) flanges have not been taken into account. Likewise, some of the formulas for monosymmetric shapes are approximations which are only valid within a certain range of param.

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