A Constant Force Spring is a precision-engineered spring designed to deliver a nearly uniform force throughout its entire range of motion. Unlike conventional compression or extension springs, which increase or decrease force as they move, a constant force spring maintains steady output regardless of extension length. It is typically manufactured from high-quality spring steel or stainless steel and formed as a tightly wound strip that unrolls smoothly, ensuring consistent performance even in compact or repetitive-motion applications.
Constant force springs are widely used in applications where controlled, reliable, and repeatable force is critical. Common uses include cable balancers, retracting mechanisms, medical devices, automotive systems, electrical equipment, window and door systems, and industrial automation. Their advantages include compact design, long fatigue life, smooth operation, and minimal force variation. Because of these benefits, constant force springs are preferred where space is limited and precision, durability, and efficiency are essential.