Springs Compression springs Extension spring Blank Wire diameter 3mm 6mm

Start with three key dimensions: wire diameter, outer diameter (OD), and free length. Wire diameter determines the spring's stiffness and load capacity — 3mm wire is suited for lighter-duty applications, while 6mm wire handles heavier loads. OD must clear the bore or housing it sits in, and free length should match your required travel plus any preload. Use the Size variant selector above to find the combination that fits your assembly.

A compression spring is designed to resist a compressive (pushing) force — it shortens under load and returns to its free length when released. An extension spring is designed to resist a tensile (pulling) force — it stretches under load and contracts back when released. Both types are available in this listing; select the appropriate spring type based on how force is applied in your mechanism.

These springs are made from steel wire. Standard steel wire springs offer moderate corrosion resistance suitable for indoor, dry environments. For applications exposed to moisture, chemicals, or outdoor conditions, consider adding a protective coating or contact us to confirm suitability for your specific environment.

Yes. These blank spring stocks are well-suited for DIY automation rigs, robotic return mechanisms, 3D printer bed leveling, and similar maker applications. Confirm the wire diameter, OD, and free length match your design tolerances before ordering. For high-cycle or safety-critical applications, verify the spring rate and fatigue life requirements against your design specifications.

Wire diameter directly affects spring stiffness (spring rate) and load capacity. The 3mm wire variants are lighter and more compact, covering ODs of 20–40mm and lengths up to 200mm — ideal for small mechanisms, fixtures, and light-duty assemblies. The 6mm wire variants are stiffer and longer (ODs 28–47mm, lengths up to 355mm), suited for heavier-duty or longer-travel applications. Choose based on the force and deflection your design requires.

Pack quantity is shown in the Quantities(PCS) variant selector alongside the Size selector. Smaller or more specialized sizes (such as the 6mm wire variants) are typically sold in packs of 1 or 2, while the more common 3mm wire sizes are available in packs of 5. Select both the Size and Quantities(PCS) options above to confirm the exact pack you are ordering before adding to cart.

These are supplied as blank spring stock, which means they can be trimmed or modified by experienced users with appropriate tools. However, cutting a spring alters its spring rate and end geometry, which may affect performance. For best results, select the variant closest to your required free length rather than modifying a longer spring.