How Load Capacity is Determined
The load capacity of a steel beam is determined by its resistance to bending, which is a function of its cross-sectional shape and the yield strength of the steel. The shape's resistance is quantified by its Section Modulus (S).
The formula for maximum bending moment (M) a beam can resist is M = Yield Strength × Section Modulus. By rearranging the formula for a center-loaded beam (M = (Load × Span) / 4), we can solve for the maximum load: Load = (4 × Yield Strength × S) / Span. This calculator provides this value, ensuring the beam is not overstressed.