What is a Wire Compression Spring?

Compression springs are designed to absorb, store, and release energy when a squeezing or compressing load is applied to them. They are open-coiled, meaning there is a designed gap (pitch) between the working coils when the spring is at rest.

Imagine you’re holding a slinky between your hands and pushing your palms together. The resistance you feel  is a compression spring at work. When a linear force pushes against the flat ends, those open coils are forced to squeeze together.

But here is the cool engineering secret: even though you are pushing down on the spring, the wire itself isn't actually experiencing compression. Instead, that axial energy gets twisted into torsional stress along the helix of the wire. Think of it like wringing out a towel; as you push down, you are essentially twisting the wire. Once you let go, that stored mechanical energy unwinds, forcing the coils back outward to their original free length.

If your assembly relies on a pushing force, you can find thousands of immediate options in our stock compression spring catalog. Alternatively, drop your exact dimensions into our interactive compression spring calculator to instantly check live inventory or generate a custom manufacturing quote.

What is a Wire Torsion Spring?

Unlike compression variants, torsion springs exert an angular, rotational force known as torque. The coils are wound tightly together or with a small pitch, and the spring features straight extensions of wire on either end called "legs."

Think about the last time you used a standard wooden clothespin. You pinch the raw wooden ends together, and the jaw snaps shut. That is a torsion spring doing its job.

When you rotate the legs of a torsion spring around its central axis, you are applying a bending moment. As you twist those legs to wind the spring tighter, something fascinating happens: the coils contract radially. The entire body of the spring actually shrinks in diameter and grows just a little bit longer. Unlike the compression spring, the wire here experiences bending stress; the outside curve of the wire stretches in tension, while the inside curve squeezes in compression.

⚠️ Critical Design Tip: Because the inner diameter (ID) of a torsion spring physically shrinks as you load it, you have to be careful! You must always ensure there is enough clearance between the inside of the coils and any mounting mandrel or shaft so the spring doesn't bind up, seize, and snap.

Because the legs of a torsion spring often require highly specific custom bends or offsets to anchor into your device, standard inventory might require modifications. You can check our online catalog for stock options or configure custom leg geometries via our torsion spring calculator for rapid-turnaround pricing.

What is a Extension Spring?

Extension springs operate on the exact opposite mechanical principle of compression springs. They are wound tightly together with a parameter called initial tension; an internal force that keeps the coils securely pressed against one another until a threshold load is met.

Picture a classic backyard trampoline. To get that bouncy surface, the black mat is hooked to the steel frame by dozens of tightly wound springs. When you jump on the mat, you pull those hooks apart, stretching the springs out.

Extension springs absolutely hate being pulled apart. They are manufactured with "initial tension," which is an internal force built right into the metal during coiling that forces the loops to tightly hug each other. Until your pulling force overcomes that initial tension, the spring won't budge an inch. Once it does stretch, it stores energy through torsional stress inside the wire, constantly fighting with everything it has to pull those hooks back together to its original resting length.

Finding the perfect balance of initial tension and hook style (such as crossover loops or extended hooks) can be a fine line. Use our extension spring finder tool to scan our massive inventory dynamically, or manipulate your load properties using our extension spring calculator to receive scaled pricing from 25 to 25,000 units alongside a rapid ISQ.

What is a Conical Spring?

Conical springs are a specialized geometry variation of the standard compression spring. Instead of maintaining a uniform outer diameter from top to bottom, the coil diameters are progressively modified to give the component a distinct cone or tapered profile.

Imagine a standard spiral notebook spring vs. a volcano or an ice cream cone. Conical springs look just like that cone. You push down on them just like a regular compression spring, but their tapered shape unlocks two incredible mechanical superpowers.

First, there is the telescope effect. Because the top coils are smaller than the bottom ones, they don’t hit each other when you push down. Instead, they nest perfectly inside one another like a collapsible travel cup. This means you can compress the spring down until it's practically as flat as a single strand of wire!

Second, they give you a non-linear spring rate. In a normal spring, the pushback is steady and predictable. But with a cone spring, the large coils at the bottom are wider and weaker, so they compress first. Once they flatten out and drop out of the equation, the smaller, stiffer coils at the top take over. The result? The harder you push, the more aggressively stiffer the spring gets. Plus, that wide base gives it incredible balance, meaning it won’t bow or buckle sideways even without a rod down the center.

If your assembly has tight spatial limits or requires a complex progressive force profile, query our catalog using the wire cone spring finder to locate an off-the-shelf solution that fits your envelope.