Question

For the three bolt system shown in the figure, the bolt material has shear yield strength of $200MPa$. For a factor of safety of $2$, the minimum metric specification required for the bolt is

• A. $M16$
• B. $M12$
• C. $M8$
• D. $M10$

Answer 1

The correct option is D $M10$

Design stress = $\frac{{\tau }_y}{FOS}=\frac{200}{2}$
$=100MPa$
Load= $19kN$
Total shear area = $\frac{19\times {10}^3}{100\times {10}^6}$
$=1.9\times {10}^{-4}{m}^2$
Shear area for one bolt = $\frac{A}{3}=6.33\times {10}^{-5}{m}^2$
$\therefore d={\left(\frac{4\times 6.33\times {10}^{-5}}{\pi }\right)}^{1/2}$
$=8.982\times {10}^{-3}m$
$=8.982m$
So, $M10$