Compression Spring Wire Dia 0.5mm 304 Stainless Pressure Coil Springs OD 3-15mm

Measure the bore (hole) or guide rod your spring will seat in or around. For a bore-mounted spring, the OD should be slightly smaller than the bore diameter — typically 0.2–0.5mm clearance. For a guide-rod spring, the inner diameter (ID = OD minus 2× wire diameter, so ID ≈ OD − 1mm for this 0.5mm wire) should be slightly larger than the rod. Select the matching OD variant from the dropdown above.

With a 0.5mm wire diameter, these are light-duty springs suited for low-force applications such as button returns, pen clips, small latches, and sensor contacts. Exact load capacity depends on the OD and free length of the specific variant. For higher-load requirements, consider a thicker wire diameter. Contact us if you need spring rate data for a specific variant.

304 stainless steel offers good resistance to atmospheric corrosion, fresh water, and mild chemical exposure. It is suitable for indoor humid environments, light outdoor use, and non-chlorinated water contact. For marine, saltwater, or strongly acidic/alkaline environments, 316 stainless steel would be a more appropriate choice.

The outer diameter (OD) is the overall outside measurement of the coil. The inner diameter (ID) is approximately OD minus twice the wire diameter. For these 0.5mm wire springs, ID ≈ OD − 1mm. For example, a 5mm OD spring has an ID of approximately 4mm. Use the ID when sizing the spring around a guide rod.

Yes. The fine 0.5mm wire and small OD options (3mm, 4mm, 5mm) make these springs well-suited for PCB-mounted spring contacts, battery terminals, tactile switch returns, and probe pin assemblies. The uncoated stainless surface is electrically conductive, which can be an advantage in contact spring applications.

If you are prototyping or need a specific size for a one-off repair, the 1 or 2-piece packs are the most economical entry point. For small production runs or workshop stock, the 10 or 20-piece packs offer a lower per-unit cost. The 5-piece pack is a good middle ground for small batch testing before committing to larger quantities.

Free length is the overall length of the spring when it is not compressed or stretched — its natural resting state. When installed, the spring will be compressed to a shorter "installed length." Ensure the free length is longer than your required installed length, and that the compressed length (solid height) is shorter than your available space. For this product, free lengths range from 5mm to 305mm across variants.