A helical spring is a type of mechanical spring made from a coiled wire that is wound in a helix shape. These springs are designed to store and release energy when they are compressed or stretched. They are commonly used in various applications, such as in automobiles, furniture, and industrial machinery, to absorb shock and provide support. Helical springs can be classified into two main types: compression springs and tension springs. Compression springs are designed to resist compressive forces, while tension springs are made to resist pulling forces. The design and material of helical springs can vary, allowing them to be tailored for specific uses and load requirements.