coilspring

Coilspring, commonly referred to as a coil spring, is a mechanical device made of a helically wound wire designed to store and release energy through axial deformation. Depending on its geometry and loading, it resists compressive, tensile, or torsional forces, behaving according to Hooke’s law for small deformations.

The most common configurations are compression springs, extension springs, and torsion springs. Compression springs are wound to provide resistance when compressed and tend to push back to their original length. Extension springs resist extension and typically have hooks or attachments at each end. Torsion springs resist twisting and store energy when rotated, exerting torque as they unwind.

Key design parameters include wire diameter, mean coil diameter, number of active coils, free length, and solid height. Material choices span carbon steel, alloy steel, stainless steel, and specialty alloys such as phosphor bronze or beryllium copper, chosen for strength, fatigue resistance, corrosion resistance, and temperature performance. Manufacturing involves winding the wire, heat treating to temper or harden, and applying surface finishing or coatings. End configurations for compression springs (ground, squared and closed; open ends) and attachments for extension springs are tailored to application needs.

Applications are broad and include automotive suspensions, industrial machinery, consumer electronics, HVAC systems, and aerospace actuators. Important design considerations include fatigue life, load limits, minimum and maximum deflection, crowning effects, and potential for buckling or coil binding. Maintenance focuses on inspecting for cracks, corrosion, and excessive wear, and selecting materials and coatings appropriate to operating temperature and environment.