Shear stress
  • As mentioned previously, shear stress is the type of stress that features one plane sliding over another.
  • Also mentioned before is that the effective area in calculating shear stress is PARALLEL to the external force.
  • This makes the formula to calculate shear stress:
\begin{align} \sigma_s = \frac{L}{A_s} \end{align}


  • $\sigma_s$ is the shear stress (Pa)
  • $L$ is the external force/Load (N)
  • $A_s$ is the shear area ($m^2$)
  • Note that there are about 3 different ways shear stress can take place:
    • Single shear stress
      • This is the most simple of the shear stresses.
      • For a situation like (1), the shear force would be acting on the cross sectional area of the bolt(blue).
      • Thus, the shear area would be the bolt's CSA. Then simply apply the formula to calculate the shear stress.
    • Double shear stress
      • This is when a situation like (2) occurs.
      • The shear force would still be acting on the CSA of the bolt, but it's on 2 different planes.
      • Thus the shear area would be DOUBLE the bolt's CSA.
    • Punching shear stress
      • This is a special case where the where the operation punches a hole in a plate
      • In a case like (3), the shear stress in the plate acts on the hole's "edge" (blue)
      • Thus, the shear area would be the perimeter of the hole multiplied by the thickness of the material.