Compression springs are wound or constructed to oppose compression along the axis of wind. They can be wound in constant or variable pitch along their length, be constructed of stacked spring elements, and can be straight, conical, or have a variable diameter.
Specialty springs are designed for specialized or proprietary applications. There are several types of industrial springs including a steel spring, stainless steel spring, steel wire spring, leaf springs, coil springs, and industrial springs.
Extension springs are wound to oppose extension. They are often fully compressed in the no-load position and have hooks, eyes, or other interface geometry at the ends to attach to the components they connect.
Torsion springs are designed and wound to be actuated rotationally, and to provide an angular return force. They are used in all types of hinges and assemblies such as self-closing doors and lids.