Extension Springs for Off Applications - DDM Garage Doors

Some look for extension springs to use for a project other than for a garage door. Therefore, you’ll need to calculate the pull needed when the spring is fully extended. For example, if you want to ease the lift of a 300-pound object. Then, you will need an extension spring that pulls 300 pounds when it is fully extended. A 25-inch spring that pulls 300 pounds on a 7-foot high door does not pull 300 pounds until it is stretched 42 inches beyond its original length of 25 inches. The total extended length of the spring would then be 67 inches.

Here are two variations to consider. If you cut the 300-pound lift extension spring in half, it would pull 300 pounds when stretched only 21 inches. However, if you pull the same 25-inch spring just 21 inches, it will pull only 150 pounds. If you determine what you need for your special application, we can usually find a solution.

Please contact us with any questions that you may have.