Required information

For the C clamp shown, a force is applied at the end of the $0\mathrm{.}375$ in diameter handle. The screw is a $0\mathrm{.}75$ in$-6$ Acme thread $($from Figure $8-3),$ and is $10\mathrm{.}80$ in long overall, with a maximum of $8$ in possible in the clamping region. The handle and screw are both made from cold$-$drawn AISI $1006$ steel. The coefficients of friction for the screw and the collar are $0\mathrm{.}15.$ The collar, which in this case is the anvil striker's swivel joint, has a friction diameter of $1$ in$.$ It is desired that the handle will yield before the screw will fail.

where $\backslash (\backslash$mathrm$\{$L$\}=3\mathrm{.}900\backslash )$ in

Determine a factor of safety for buckling of the screw. $($Round the final answer to three decimal places.$)$

The factor of safety is