10Pcs Compression Spring Steel 0.8mm Wire Dia 4 - 12mm OD Small Pressure Springs

Measure the bore or housing that will guide the spring. The spring's outer diameter should be slightly smaller than the bore to allow free movement without binding. For a spring seat or post, the inner diameter of the spring should clear the post with a small gap. Select the OD variant closest to your required fit from the options above.

Free length is the uncompressed length of the spring. Choose a free length longer than your required working travel plus the solid height. As a conservative rule, the working deflection should not exceed 70–80% of the free length to avoid coil bind and fatigue. Available lengths range from 5 mm to 50 mm — select the variant that fits your assembly's travel requirement.

With a 0.7 mm wire diameter, these springs are designed for light-to-medium load applications. Typical use cases include pen mechanisms, button returns, contact pressure in electronics, and small fixture clamps. For heavy-duty industrial loads, a larger wire diameter would be more appropriate. Exact spring rate varies by OD and free length — contact us to confirm if you have a specific load requirement.

These springs are made from steel wire. Standard steel offers good mechanical properties but has limited corrosion resistance in humid or wet environments. For outdoor or moisture-exposed applications, consider applying a light coat of machine oil or using them in a protected enclosure. If corrosion resistance is critical, contact us to confirm available finish options.

Yes — the 4 mm and 5 mm OD variants with shorter free lengths (5–15 mm) are commonly used in pen click mechanisms, push-button returns, and small latching assemblies. Verify the OD and free length against your existing spring dimensions before ordering to ensure a direct fit.

Absolutely. These small compression springs are popular in DIY robotics for joint return mechanisms, gripper fingers, and contact probes. In electronics, they are used for battery contacts, PCB test fixtures, and connector retention. The 10-piece pack is ideal for prototyping multiple positions or testing different spring rates across your design iterations.

Spring rate increases with larger wire diameter and shorter free length, and decreases with larger OD and longer free length. Since all variants share the same 0.7 mm wire diameter, a shorter free length or smaller OD will generally give a stiffer spring. If you need a specific spring rate value, contact us with your OD and free length selection and we can provide further guidance.