Garage Door Tension Springs
A garage door's spring system is its most important component, because it determines how easily and smoothly the door opens. The most popular type of spring system is the tension spring system, because it is compatible with double doors, unlike extension springs, which only work with single-car garage doors.
What Is a Garage Door Tension Spring?
A tension spring is a large version of a torsion spring, and works by winding up into a coil as the garage door closes. It uses a shaft, spring, and drum assembly. A tension spring system consists of one or two springs, usually made of hardened and tempered steel, which are mounted above the garage door, just above the header. The tension spring counterbalances the weight of garage door, distributing the weight more evenly, and allowing the door to be opened by a person or by an automatic door opener. A tension spring consists of a torsion shaft that lifts the drums, which then wind the cables attached near the bottom of the door.
Types and Sizes of Tension Springs
Tension springs are made from several materials, including music wire, hard-drawn steel, stainless steel, and non-metal materials. Tension springs come in several standardized sizes, and are measured based on four factors: the thickness of the wire, the inside diameter of the relaxed coil, the length of the relaxed spring coil, and the direction of the winding of the spring. The most common wire sizes used in the United States are 0.207", 0.218", 0.225", 0.234", 0.243", 0.250", and 0.262".
Tension Springs and Safety Issues
A tension spring holds a large amount of tension, and the energy released by one is so strong that maintenance should only be performed by a professional. Because the tension spring controls the opening and closing of the garage door, setting the tension correctly is vital to the proper functioning of the door. The tension spring should be attached to safety cables, to prevent the spring from flying off if it breaks and causing damage to property or injury to people.
Maintenance of Tension Springs
Tension springs have a life span of about 10,000 cycles, and if the system consists of two springs, it is recommended that both are replaced at the same time. After several years, the force of operating the door causes stress on the springs, causing them to break. Springs should be replaced with models fitted specifically for the kind of garage door. Tension springs can be wound three ways: right hand, left hand, and double. Double wind springs usually have both a left-hand and a right-hand wind, with an unwound section between.
For more general information on garage doors see the following article from HomeDoctor.net: Garages Doors at Home.