How are extension springs measured?

Measure the free length of the extension spring by measuring to the inside edge of end to end of each hook or looped end.

Can you shorten an extension spring?

How to Cut Continuous Length Extension Springs. Fold the spring 180° at desired length and cut. Cut shorter than needed by one-half the coil body diameter.

What is the length of coil springs?

To calculate spring wire length per coil, you must subtract the wire diameter from the outer diameter in order to get mean diameter. Once you have calculated mean diameter, multiply it by pi (3.14); this will give you the length of wire per coil.

How do I know what extension spring I need for my garage door?

For a one car garage door, carefully lower the garage door onto a bathroom scale in the center of the garage door. Read the scale. The weight that shows on the bathroom scale is the size extension spring you need to order. For a two car garage door, carefully lower the garage door on to two bathroom scales.

What is the free length of a extension spring?

Free Length – is the overall dimension of an extension spring in the unloaded position. The free length is measured from the inside of one end loop (or hook) to the other and can be varied by changing the end configuration without changing the number of coils.

What is extension spring?

Extension springs absorb and store energy as well as create a resistance to a pulling force. These springs are normally attached at both ends to other components and when these components move apart, the spring tries to bring them back together again.

Do garage door extension springs come in different lengths?

Height of the door Extension springs vary in length. Springs that work for a standard height door won’t work for an extra tall door because the springs will need to extend farther.

What is the solid length of a spring?

The shut height or solid length is the length of the spring when the spring is loaded such that the coils are actually touching. This is the shortest possible length for the spring without crushing it beyond all recognition.

Is it OK to cut coil springs?

The only coil springs that can be safely cut are coil springs with tangential ends. Because Square ends and Pigtail ends are designed to make full contact with their mounting points, they would have to be re-shaped after they were cut.

Is Longer spring better?

The key takeaway from the above discussion is that a longer spring means more preload, which means that at any given point in the stem’s travel, the actual force being exerted against your fingers will have less to do with how far you have pressed the switch, and more to do with the preload.

How long do extension springs last?

Extension Springs’ Life Expectancy: Extension springs are installed at the side of the door and act extend, rather than contract (as does the torsion spring). They have 15,000 and 20,000 cycles which equate 7 – 12 years of life expectancy.