At North Shore Commercial Door.com, we offer a full selection of garage door springs, from torsion springs and torque master to mini warehouse springs and extension springs. Garage door extension springs work by using springs, cables and pulleys that are attached to the bottom of the door. When the door is closing, the springs are stretched out, and when the door is opening, the energy stored in the extended springs lift the heavy door without pulling strain on the operator. The most common type of garage door system is a torsion spring system. Torsion springs work by winding. As the door comes down, cables that are attached to the bottom of the door cause the spring to wind up and this creates stored energy. When the door is open, the springs unwind with stored energy and help lift the garage door. We also carry the very popular mini warehouse springs, specifically designed for mini warehouse doors. These springs are sourced and manufactured in the USA from 100% US steel and are oil tempered the same as all of the springs we sell. Another popular choice for garage door spring is the Wayne Dalton Torxmasters spring. While those springs have had a bad reputation for easily breaking in the past, they have been revised and improved to be an excellent choice. Torxmasters springs have a low profile look and work exclusively with Wayne Dalton doors. A good door spring will enable your door to be pulled up and down easily and maintain any position you set the door at. So if the door is heavy or slides down by itself, when not connected to the operator, the spring may be out of adjustment or possibly broken. When spring is put a strain on your garage door operator gears and will cause the garage door to be supported only by the operator chain, which can be dangerous when the door is lifted by free falling at any moment. Garage door springs are designed to withstand 10,000 open closed cycles and often break afterwards and should be immediately replaced. When ordering garage door spring replacements, keep in mind it's best to replace both springs even though only one is broken. Since the springs are designed to work for a pre-determined number of cycles, you'll save time and money by replacing both whenever a spring breaks.