Power spring is the steel strip wound on an arbor and confined in a spring case. When a force rotates the spring, arbor will have relative motion with spring case and store rotational energy in the form of torque. When the force is removed, torque releases through the central arbor or the spring case in which it is restrained. The product range from 0.03~0.75mm in thickness and 1~50mm in width.

Ming Tai applied power spring in precision pen medicine injector, which has great performance and acquires high affirmation from the suppliers of drug delivery systems. The new type of precision pen medicine injector uses a distinctive power spring to deliver small but highly accurate doses of medicament.