# Why are springs spiral-shaped? [duplicate]

I've had this question on my mind for quite a while and looking at the web, I couldn't find an answer to this question.

I've had a lot of physics experiments involving springs, unintentionally dismantled a hair clipper once, helped my dad repair his car, and all of them have very identical springs.

Here's an image of a variety of springs that are used for multiple purposes:

So, what's with the spiral/helical shape? And why are they "curled" in circle-like shapes. Why not triangle, square or any other geometric shape? What exactly is the physics behind this.

• ":spiral shape" Helical shape? – DJohnM Jun 26 '19 at 8:55
• Although I am sure, my intuition says that the gap between two turns has to do with the spring constant. $k=Y\frac{A}{L}$, where $Y$ is Young's Modulus, $A$ is cross-sectional area and $L$ is the length of spring. You can also visit this page springhouston.com/spring-information/spring-engineering.html – Jitendra Jun 26 '19 at 9:07
• Not all springs are based on a spiral, many vehicles have flat springs, some door locks have flat springs... – user207455 Jun 26 '19 at 10:22
• @ GiorgioP Yes, it's indeed a very similar question, but the user didn't ask regarding the shape of the spring. So a separate question is needed. – user226894 Jun 26 '19 at 11:06
• There is another aspect of this that should be mentioned. If you have a straight rod of the same diameter as the spring metal, you can stretch it very little before it exceeds its elastic limit, and the force would be very large, while the elongation would be tiny. The mode of deformation here is uniaxial extension. But, if the same metal rod is wound in a helical coil, the resulting spring can be extended a large amount without exceeding the elastic limit of the metal, and the force will be much more reasonable. The mode of deformation here is shear between adjacent metal cross sections. – Chet Miller Jun 26 '19 at 23:26