Compression Spring 0.4mm Wire Dia 5-12mm Dia 5-100mm Length A2 Stainless Steel

Measure the bore or housing your spring will sit in and select an OD at least 0.5–1mm smaller than the bore for clearance. For free length, choose a spring that is 20–30% longer than your required compressed length to keep the spring within its elastic range and avoid coil bind.

Spring rate varies by OD and free length combination. Shorter springs with smaller OD will have a higher rate; longer springs with larger OD will be softer. Exact spring rate data per variant is available on request — contact us to confirm before ordering for load-critical applications.

Yes. A2 (Grade 304) stainless steel offers good resistance to atmospheric corrosion, fresh water, and mild chemical exposure. For marine or chloride-rich environments, consider A4 (Grade 316) stainless instead, as 304 can be susceptible to pitting in high-salt conditions.

A2 stainless steel retains adequate mechanical properties up to approximately 250–300°C (480–570°F) for intermittent use. For continuous elevated-temperature service above this range, a high-temperature alloy spring would be more appropriate.

These springs follow standard coil geometry with closed and ground ends, making them compatible with most off-the-shelf spring seats, plunger housings, and guide pins. Verify that your seat ID is slightly larger than the spring OD and that the guide pin OD is slightly smaller than the spring ID (OD minus twice the wire diameter).

For prototyping and testing, the 5 or 10-piece pack lets you validate fit and spring rate without over-committing. Once your design is confirmed, the 50 or 100-piece pack offers better per-unit value for small production runs or ongoing maintenance stock.

The inner diameter equals the outer diameter minus twice the wire diameter. For example, a 0.4x8mm spring has an ID of approximately 8 – (2 × 0.4) = 7.2mm. Use this to size your guide pin correctly and prevent lateral buckling under load.