Industrial springs include models designed to absorb impact, expand and elongate, or maintain pressure in various applications. Compression springs shorten under loads to absorb impact and protect against shock impact in mechanical applications like welding, valve and pipe-fitting, and automotive engine systems. Disc springs have a convex shape that generates high force within a very short length. They are used when a large load is required in a limited space, and they can return to their original height even after repeated cycling. Extension springs expand and elongate under loads. They can be used in compatible garage doors, farm machinery, and washing devices. Torsion springs have ends that rotate in angular deflection to offer resistance to externally applied torque. Common torsion spring uses include clothespins, clipboards, swing-down tailgates, and garage doors.