Spring has officially arrived.

The grass is green again. The birds are chirping. And maybe, just maybe, you’re thinking about that long list of home projects that didn’t get done last fall. But before you pick up the power washer or fire up the lawnmower, take a closer look around you. Odds are, you’ll find a different kind of spring hiding in plain sight.

Not the season. The metal kind.

Springs are everywhere. Inside your household cleaners. Beneath your mower deck. Behind your garage door. They’re small, tightly wound, often overlooked—and absolutely essential.

So, in this edition of “How It’s Made” with FlexTrades, we’re talking about the mechanics, materials, and manufacturing behind the humble spring.

Types of Springs

Springs come in two basic types—stretched and coiled.

  • Stretched springs store energy when pulled, like the tension in a bow and arrow. Pull back the string, and the spring (the bow) transfers energy to the arrow in a snap.
  • Coiled springs are the most common. They compress and expand to absorb shock, maintain pressure, or return components to a resting state. The first patent for a coiled spring dates back to 1763. The design has endured for a reason.

How Springs Are Made

No matter the style, the spring manufacturing process is surprisingly precise—and it all starts with the right material.

Materials

Springs are made from a wide range of materials based on end-use needs:

  • Stainless steel
  • Non-ferrous alloys like Monel
  • High-temperature alloys such as Inconel
  • High-carbon and alloy steels
  • Plastics (for specialty applications)

Design

Every spring is engineered with precision. The design process involves a surprising amount of math—factors like diameter, length, wire thickness, number of coils, and the amount of force needed are all carefully calculated to match the demands of the application.

Coiling

Once the specs are locked in, it’s time to wind. Coiling machines shape the material using either:

  • Cold winding for most wire types
  • Hot winding for thicker wire or bar stock

Not sure how a spring coiler works? Check out Automated Industrial Motion—they break it down with incredible detail.

Tempering

Tempering strengthens the spring and removes stress left over from the coiling process. Springs are exposed to extremely high temperatures for a set amount of time. The result? Better performance and durability under load.

Finishing

From grinding to coating, the final steps are all about getting the spring ready for real-world use.

  • Grinding flattens the ends of the wire
  • Shot peening smooths the surface and prepares for coating
  • Setting ensures the spring holds its shape under stress
  • Coating protects against corrosion
  • Quality control checks for exact performance specs

If you want to see the process in action, here’s a great visual to walk you through it.

Final Thoughts

Springs aren’t just for trampolines. They’re everywhere. And understanding how they’re made? That’s just one more way we at FlexTrades celebrate the people and processes that keep manufacturing moving.