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When your project demands reliable spring force in an extremely confined space, standard springs simply won't fit. Engineers, robotics builders, and precision DIY makers working on miniature mechanisms, sensor assemblies, or micro-actuators need springs that are dimensionally consistent and corrosion-resistant right out of the bag. These micro compression springs are wound from 0.25mm 304 stainless steel wire, delivering consistent load performance in the smallest of assemblies.
Each spring is formed from 304 stainless steel wire with a diameter of 0.25mm (approx. 0.010 in). Outer diameters span 2mm, 2.5mm, 3mm, and 4mm (approx. 0.079–0.157 in), with free lengths ranging from 5mm to 50mm (approx. 0.197–1.969 in). Quantity options run from 10 to 200 pieces per order, letting you stock exactly what your build requires.
Typical use cases include miniature compression spring for electronics enclosures, small stainless steel coil spring for pen mechanisms and clicker assemblies, and micro return spring for CNC tooling fixtures, robotics joints, and precision instrument housings.
Wound from 304-grade stainless steel wire for solid corrosion resistance in humid, mildly acidic, or outdoor environments without surface treatment.
Consistent 0.25mm wire gauge across all variants ensures predictable spring rate and reliable dimensional tolerance for micro-scale assemblies.
Four outer diameters (2mm, 2.5mm, 3mm, 4mm) combined with ten free lengths (5–50mm) give you a broad selection to match your exact bore and travel requirements.
Available in 10, 30, 50, 100, and 200-piece packs — order a small trial batch or stock up for production runs without overpaying for excess inventory.
Uniform coil pitch throughout the spring body ensures even load distribution and prevents buckling under axial compression in precision guide channels.
Ideal for pen mechanisms, micro-switches, sensor probes, robotics joints, CNC tooling fixtures, and any miniature return-spring application requiring a compact footprint.
| Material | 304 Stainless Steel |
|---|---|
| Wire Diameter | 0.25mm (approx. 0.010 in) |
| Outer Diameter (OD) | 2mm / 2.5mm / 3mm / 4mm (see variant options) |
| Free Length | 5mm – 50mm (see variant options) |
| Spring Type | Compression (open-end coil) |
| Coil Direction | Right-hand wound (standard) |
| Surface Finish | Natural / Bright (no coating) |
| Spring Rate | See variant options |
| End Type | Open ends (standard) |
| Quantity per Pack | 10 / 30 / 50 / 100 / 200 pcs (see variant options) |
Measure the inner diameter of the bore or housing where the spring will sit. The spring's outer diameter should be slightly smaller than the bore ID to allow free movement without binding. For shaft-guided applications, the spring's inner diameter (OD minus 2× wire diameter) should be slightly larger than the shaft. Select from OD 2mm, 2.5mm, 3mm, or 4mm based on your clearance requirements.
Free length is the uncompressed length of the spring. Choose a free length that is longer than your required working length (compressed length + desired travel). Available options range from 5mm to 50mm in this listing. If you need a specific compressed height, contact us to confirm the solid height for your chosen variant.
304 stainless steel offers good resistance to oxidation, moisture, and mild chemical exposure, making it suitable for indoor electronics, light outdoor use, and humid environments. It is not recommended for prolonged immersion in chloride-rich solutions (e.g., seawater). For highly corrosive environments, consider 316 stainless steel alternatives.
304 stainless steel retains its mechanical properties up to approximately 300–400°C (572–752°F) for short-term exposure. For continuous high-temperature service above 250°C, spring rate and load capacity may decrease. Contact us to confirm suitability for your specific temperature range.
Yes. These micro compression springs are commonly used in CNC tooling fixtures, robotic joint return mechanisms, sensor probe assemblies, and precision actuator housings. Their small OD (2–4mm) and consistent wire diameter make them well-suited for tight-tolerance mechanical designs. Verify the spring rate matches your load requirements before finalizing your design.
The 10-piece pack is ideal for prototyping, testing fit, and verifying spring rate before committing to a larger order. The 30, 50, 100, and 200-piece packs offer a lower per-unit cost and are suited for small production runs, repair stock, or projects requiring multiple springs. Select the quantity that matches your current build volume to minimize waste.
The inner diameter (ID) equals the outer diameter minus twice the wire diameter. For example: OD 2mm − (2 × 0.25mm) = 1.5mm ID; OD 2.5mm = 2.0mm ID; OD 3mm = 2.5mm ID; OD 4mm = 3.5mm ID. Use these values to confirm shaft clearance in guided spring applications.
