Steel wire exhibits strong tensile strength, allowing it to function as an elastic spring when coiled. The coiling process enables the wire to withstand twisting motions and opposing torques, similar to how a straight rod would resist such forces. Stress and strain can be analyzed in both the straight and coiled forms under torque applications. When loaded axially, the coiled spring's resistance to shear and bending can be neglected, focusing solely on the axial load. Understanding these principles can clarify the mechanical behavior of steel wire in spring applications.