A flat tension spring is a type of mechanical spring that is characterized by its flat shape and ability to exert a force when stretched or compressed. It is commonly used in various applications where a pulling or pushing force is required. The flat design allows for easy installation and efficient operation.

It is a pre-stressed flat strip of spring material which is formed into virtually constant radius coils around itself or on a drum. When the strip is extended (deflected) the inherent stress resists the loading force, the same as a common extension spring, but at a nearly constant (zero) rate.

Flat springs are strips or bars of metal, or assemblies of such, that are formed to produce a repeatable counterforce when compressed or displaced and used for positioning or contacting. Key specifications include the intended application, flat spring type, and spring ends type.