How to Measure the Strength of an Angle Iron

Measure the dimensions of your angle iron with a tape measure. You'll need to know the width and depth of the bar, as well as the combined lengths of both sides. Measure the force that is working against the angle iron. Multiply that force by 3, and then multiply that product by the combined length.

Multiply the depth by itself, then multiply that product by twice the iron's width.

Take the answer you calculated in the first step and divide it by the result from the second step. The quotient will be your angle iron's strength against forces trying to pull the iron apart.