Prob. $4(15\mathrm{.}19)(2)$

Following figure depicts a partial section from a permanent connection. Find:

a$.$ The total force and stress in each bolt $($in kips & ksi$).$

b$.$ The tightening torque for an average condition of thread friction $($in kip$$in$).$

Given: A total of six bolts are used to resist an external load of $P=18$kips. Use: Table $15\mathrm{.}1,15\mathrm{.}4,$ Eq$.(15\mathrm{.}34).$

Assume: threaded length of the fastening part $=0$

TABLE $15\mathrm{.}4$

SAE Specifications and Strengths for Steel Bolts

$\backslash$table$[[\backslash$table$[[$SAE$],[$Grade$]],\backslash$table$[[$Size Range$],[$Diameter$,d($in$.)]],$ Proof Strength,$\text{'}$

$q,S_p(ksi),$Yield Strength, ${?}^{**}$ S$,($ksi$),$Tensile Strength, ${?}^b{S}_z(ksi),$Material Carbon Content,$],[,,,,,,k_p=0\mathrm{.}58E_{p}d$