Stress is the measure of an external force acting over the cross sectional area of an object. Stress has units of force per area: N/m 2 (SI) or lb/in 2 (US). The SI units are commonly referred to as Pascals, abbreviated Pa.

Here, the general formula to calculate bearing stress, where F refers to applied load and A to the bearing area: σ Bearing Stress (σ) = F A For example, consider a bolt with a force of 2000 Newtons applied to it, and the bearing area is 50 square millimetres. Using the equation above, the bearing stress would amount to 2000 50 = 40 MPa.

In essence, bearing strength is the maximum stress load that the unit can “bear” or hold before the structure fails. But bearing strength can also be measured in terms of tensile, compression, and flexural strength, plus bearing hardness.

Bearing stress is the contact pressure between the separate bodies. It differs from compressive stress, as it is an internal stress caused by compressive forces. σb = Pb Ab σ b = P b A b