Mechanical Engineering $-$ Machine DesignFigure $1$ shows a configuration of bolted $15-$ by $200-mm$ rectangular steel bar cantilevered to a $250-mm$ steel channel using three tightly fitted bolts.

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It has been determined that from the same bolt arrangement but with different load, the critical bolt is bolt $A.$ If the load $F$ is $16kN,$ determine a suitable bolt grade if the required bolt size is $M162$ with safety factor $SF=1\mathrm{.}2.$