(Solved): The extension spring shown in the figure has full-twisted loop ends. The material is AISI 1065 OQ\ ...

The extension spring shown in the figure has full-twisted loop ends. The material is AISI 1065 OQ\&T wire. The spring has 86 coils and is close-wound with a preload of \( 18 \mathrm{lbf} \). The closed length of the spring \( L_{0} \) is in. The torsional stress in the spring corresponding to the preload \( T_{j} \) is \( p s i \). The spring rate \( k \) is \( \quad \mathrm{lbf} / \mathrm{in} \). The load that would cause permanent deformation \( F \) is \( \quad \) Ibf. The spring deflection corresponding to the load \( F, y \), is in.