Compression Spring 3mm Wire Diameter 26-29mm Dia 20-100mm Length Pressure Spring

Match the outer diameter (OD) to your bore or housing inner diameter with 0.5–1mm clearance. Select a free length roughly 20–30% longer than your required compressed length to stay within the elastic range. Use the Wire Dia × OD × Length variant selector above to find your exact combination.

Spring rate varies by outer diameter and free length — shorter springs with smaller OD are stiffer, while longer springs with larger OD are softer. Specific spring rate data is available on request; contact us to confirm before ordering for load-critical applications.

The springs carry a surface treatment that resists light moisture and oxidation, making them suitable for indoor mechanical use and light-duty outdoor applications. For continuous exposure to water, salt spray, or chemicals, consider adding a protective coating or selecting a stainless steel alternative.

Choose the OD that fits your housing bore with a small clearance (typically 0.5–1mm). If the spring will slide over a guide post, ensure the post diameter is at least 1–2mm smaller than the spring's inner diameter (OD minus twice the wire diameter). For a 26mm OD spring with 3mm wire, the inner diameter is approximately 20mm.

Yes — the cylindrical open-end design is compatible with many valve seat and pneumatic actuator configurations. Verify the free length, compressed length, and load rating against your assembly's specifications. Contact us to confirm suitability for pressure-rated or safety-critical applications.

Springs in mechanical assemblies often wear together, so replacing a set at once prevents mismatched fatigue levels. Multi-piece packs (5, 10, 20, 30, 40 pcs) also reduce per-unit cost and ensure you have spares on hand for prototyping iterations or future maintenance without reordering delays.

Measure the wire diameter with calipers, then measure the outer diameter and the free (uncompressed) length. Match all three values to the variant options listed above. If your existing spring is slightly fatigued, the free length may have shortened — measure a new spring from the same batch if possible, or add 2–5mm to account for set.