When shopping for a compression spring, you may come across some unfamiliar terms, one of which is solid height. Compression springs, of course, are energy-storing devices consisting of helical coils. They are designed to become shorter under a load.
When an object pushes against a compression spring, the spring will become shorter while subsequently pushing back with an equal force. If you’re planning to buy a compression spring, however, you should pay attention to its solid height.
What Is Solid Height?
Solid height refers to the length of a compression spring under maximum load. In other words, it’s the length of a compression spring when all of the coils are pressed together.
All compression springs become shorter under a load; that’s essentially what distinguishes them from other types of springs, such as extension springs. Whether they are made of stainless steel, aluminum or any other material, though, compression springs can only become so short under load. The solid height of a compression spring represents this length. It’s the shortest length a compression spring can become under a load.
The formula for calculating solid height is number of coils x wire diameter. If a compression spring has 15 coils and a wire diameter of 2 millimeters, for instance, its solid height would be 30 millimeters.
Why Solid Height Is Important
You can’t ignore solid height when shopping for a compression spring. If the solid height is too tall for the space in which you intend to use the compression spring, the spring won’t be able to fully compress. This can result in a loss of performance, as the compression spring won’t be able to exert a full force, or the spring may even sustain damage.
To ensure proper performance, and to protect the compression spring from damage, you need to consider its solid height. Make sure there’s enough space for the compression spring to fully compress.
Solid Height vs Free Length
There’s solid height, and there’s free length. While they both represent the length of a spring, they aren’t the same.
Solid height is the length of a compression spring under a maximum load, meaning all of its coils are pressed together. Free length, on the other hand, is the default length of a given spring without being exposed to a load. For compression springs, the free length will always be longer than the solid height.