How To Calculate The Tensile Capacity Of A U-Bolt

The tensile capacity is the maximum stress that can be applied to an object by stretching or pulling the object before it becomes structurally compromised. Determining the tensile capacity of U-bolts is important for determining the maximum loads that these bolts can handle, especially in construction and engineering applications. Calculating the tensile capacity of a U-bolt requires a bit of knowledge about the structural properties of the U-bolt material and some simple mathematics.

Step 1

Determine the cross-sectional area of the bolt. Since U-bolts are circular, this can be done by squaring the radius of the cross section of the bolt (i.e. multiplying the number by itself), then multiplying that number by the constant pi (3.14). For example, if the radius of the bolt is 0.05 inches, squaring this and multiplying by pi gives 0.785 square inches (in^2).

Step 2

Multiply the tensile strength of the material by the cross-sectional area of the bolt. You can usually obtain the tensile strength of the material from the manufacturer. For example, if the tensile strength of the bolt is 400 pounds per square inch (lbs/in^2), multiplying this by the cross-sectional area of 0.785 in^2 gives 314.16 lbs.

Step 3

Multiply the product of the tensile strength and the cross-sectional area by 0.56, a coefficient which differentiates shear capacity from tensile capacity. In our example, multiplying 314.16 pounds by 0.56 gives 175.93 pounds. This number is the tensile capacity of the U-bolt.