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When a project demands repeatable, consistent spring force in a compact envelope, undersized or mismatched springs cause premature fatigue, erratic actuation, and costly rework. Engineers, makers, and repair technicians who need dimensionally accurate compression springs in small wire gauges rely on a verified source that stocks the exact combination of wire diameter, outer diameter, and free length they need.
These compression springs are wound from 304 stainless steel wire with a diameter of 0.9 mm (approx. 0.035 in). Outer diameter spans 9–16 mm (approx. 0.35–0.63 in) and free length ranges from 10–50 mm (approx. 0.39–1.97 in). Each spring features closed and ground ends for flat, stable seating and consistent load distribution across the full deflection range.
Typical applications include small appliance mechanisms requiring a compact compression spring for button return, precision instrument assemblies needing a stainless steel miniature spring for corrosion resistance, and DIY automation or robotics builds where a 304 SS compression spring with controlled spring rate is essential for repeatable actuation.
| Material | 304 Stainless Steel |
|---|---|
| Wire Diameter | 0.9 mm (approx. 0.035 in) |
| Outer Diameter Range | 9–16 mm (approx. 0.35–0.63 in) |
| Free Length Range | 10–50 mm (approx. 0.39–1.97 in) |
| End Type | Closed and Ground |
| Spring Direction | Right-hand wound (typical) |
| Surface Finish | Bright / Natural (no coating) |
| Spring Rate | See variant options |
| Max Load | See variant options |
| Number of Active Coils | See variant options |
| Pack Quantity | 10 / 20 / 50 / 100 / 200 pcs |
Measure the bore or spring pocket your spring must fit inside — the spring's outer diameter should be 0.5–1 mm smaller than the bore for clearance. For free length, select a spring that is longer than your required working length so it remains under compression (and therefore in contact with both seats) throughout the full stroke. Use the formula: working length = free length − (load ÷ spring rate) to verify deflection.
Load capacity depends on the specific outer diameter and free length combination. Smaller outer diameters and shorter free lengths generally yield higher spring rates and lower maximum deflection. For exact spring rate and maximum load values for a specific variant, contact us to confirm — we do not publish fabricated load figures.
304 stainless steel provides good resistance to atmospheric corrosion, fresh water, and mild chemical exposure. It is not recommended for prolonged immersion in chloride-rich environments (e.g., salt water or swimming pool water) where 316 stainless steel would be more appropriate. For indoor mechanisms, humid workshops, or light outdoor use, 304 SS performs reliably without additional coating.
Yes. The closed and ground ends seat flat against standard spring pockets and plunger faces. For guided applications, the inner diameter (outer diameter minus twice the wire diameter, approximately OD − 1.8 mm) should clear the guide rod with at least 0.3–0.5 mm radial clearance to prevent binding during compression.
With the same wire diameter (0.9 mm) and free length, a larger outer diameter results in fewer active coils per unit length, which typically produces a lower spring rate (softer spring). A smaller outer diameter with the same free length has more active coils and a higher spring rate (stiffer spring). Choose based on the force-deflection curve your mechanism requires.
For prototyping or single-unit repairs, the 10-piece pack minimizes upfront cost while giving you spares for testing. For small production runs, jigs, or fixtures where you need consistent replacements on hand, the 50- or 100-piece packs reduce per-unit cost significantly. The 200-piece option (available on select variants) is suited for batch manufacturing or stocking a maintenance kit.
304 stainless steel retains adequate mechanical properties up to approximately 300°C (572°F) for intermittent exposure. Continuous operation above 200°C (392°F) may cause stress relaxation and a gradual reduction in spring force over time. For sustained high-temperature applications, consider springs made from 17-7 PH stainless steel or Inconel alloys.
