What are closed and open coil helical springs?

Helical springs are well known for their load bearing, and shock absorbent properties. These springs are differentiated into two types, depending on their coils, gaps between coils, and design. These are:

• Open Coiled Helical Springs

  These types of helical springs are referred as compression springs, as they strongly resist compression. These springs have a high pitch, which creates a large space between the coils. These large spaces give a distinct identity to these springs. Also, one can see that turns of the springs lie at inclined angles towards the helical axis. The different types of open coiled helical springs are barrel springs, barbell springs, and conical springs.

• Closed Coiled Helical Springs

  These helical spring variants are also known as extension/tension springs, and are clearly distinguishable due to hook or an eye at its ends. The closed coiled helical springs are designed to resist twisting, as well as stretching. Hence, bending stress is always negligible, when compared with torsional stress. These springs have coils that are not only closely wound, but also lie on the same helical axis. The spring have turns that lie at 90 degrees to the helical axis.

Both these types of springs have ends that are grinded to make them flat. A closed helical spring with grinded edges is known as ground and closed helical spring. The grinding also helps increase the diameter of the spring.

Open and closed types of helical springs can be easily customized by total coils, wire diameter, coil gap, wire shape, etc.