Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When a failed spring causes a mechanism to jam mid-cycle, the cost is more than the part itself. Engineers, makers, and repair technicians who work with compact actuators, sensors, and miniature assemblies need compression springs they can count on — springs that hold their load rating across hundreds of thousands of cycles without corroding, fatiguing, or losing free length. These 304 stainless steel compression springs are designed for exactly that kind of demanding, detail-oriented work.
Each spring is wound from 0.3 mm (0.012 in) stainless steel wire and is available in outside diameters of 2 mm, 3 mm, 4 mm, 5 mm, and 6 mm (approx. 0.079–0.236 in). Free lengths range from 5 mm to 305 mm (approx. 0.20–12.0 in), giving you a broad selection to match your exact travel and load requirements. Springs are sold in packs of 1, 3, 5, 6, 10, 12, 20, or 50 pieces depending on the size selected.
Typical use cases include miniature valve return springs for pneumatic and hydraulic systems, contact-force springs in electronic connectors and PCB test fixtures, and preload springs in CNC tool holders and robotic end-effectors. The corrosion-resistant 304 stainless steel construction also makes these springs well-suited for food-processing equipment, marine instrumentation, and any environment where carbon-steel springs would rust prematurely.
Wound from 304-grade stainless steel wire for reliable corrosion resistance in humid, wet, and mildly acidic environments — a significant advantage over uncoated carbon-steel alternatives.
The consistent 0.3 mm wire diameter ensures repeatable spring rate and deflection characteristics across every piece in the pack, critical for assemblies where force tolerance matters.
Five outside diameter options and over 20 free-length options let you select the exact geometry your application requires without custom tooling or minimum order quantities.
Available in packs of 1 to 50 pieces. Order a small quantity for prototyping or a larger pack for production runs and maintenance stock — all from the same product listing.
Closed and ground ends (typical for this spring class) provide a flat seating surface, improving load distribution and reducing lateral buckling during compression.
Used in CNC fixtures, robotics, electronic test equipment, miniature valves, medical devices, and consumer electronics — wherever a compact, reliable return or preload force is needed.
| Material | 304 Stainless Steel |
|---|---|
| Wire Diameter | 0.3 mm (0.012 in) |
| Outside Diameter (OD) | 2 mm / 3 mm / 4 mm / 5 mm / 6 mm (see variant options) |
| Free Length | 5 mm – 305 mm (see variant options) |
| Spring Type | Compression (pressure spring) |
| End Type | See variant options |
| Spring Rate | See variant options |
| Surface Finish | Natural stainless (no coating) |
| Pack Quantity | 1 / 3 / 5 / 6 / 10 / 12 / 20 / 50 Pcs (see variant options) |
| Operating Temperature | Typically –20°C to +200°C (–4°F to +392°F) |
| Corrosion Resistance | Good — suitable for humid and mildly corrosive environments |
Measure the bore (inner diameter of the housing) or the post (outer diameter of the guide rod) your spring will seat against. The spring OD should be slightly smaller than the bore, or the spring ID should be slightly larger than the post — typically 0.1–0.3 mm clearance. For free length, select a spring that is longer than your required compressed length plus your desired travel (stroke). If you are unsure, order a small pack of two or three candidate sizes to test fit before committing to a larger quantity.
Spring rate depends on wire diameter, outside diameter, free length, and number of active coils. With a 0.3 mm wire diameter, these are light-duty springs suited for low-force applications — typically in the range of a few grams to a few hundred grams of force depending on OD and length. For applications requiring a specific rated load or spring rate, please contact us to confirm before ordering, as exact values vary by size.
Yes. 304 stainless steel offers good resistance to atmospheric corrosion, fresh water, and mild chemical exposure. It is suitable for humid indoor environments, light outdoor use, and marine-adjacent applications where salt spray is not continuous. For highly aggressive environments (strong acids, chloride-rich saltwater immersion), consider 316 stainless steel springs instead. These springs are not coated, so the corrosion resistance comes entirely from the alloy itself.
Yes. The small wire diameter and range of OD options (2–6 mm) make these springs well-suited for spring-loaded contact pins, pogo-pin sockets, and PCB test fixtures. The 304 stainless steel is non-magnetic (austenitic), which is an advantage in sensitive electronic environments. Verify the required contact force against the spring's estimated load range for your chosen size before finalizing your design.
Shorter springs (5–50 mm) are typically used for compact mechanisms where space is limited — such as button returns, latch mechanisms, and miniature valve seats. Longer springs (60–305 mm) are used where greater travel or a softer spring rate is needed, such as in suspension-style fixtures, extended actuator returns, or applications requiring a long free length with a relatively low compressed height. Note that longer springs with a small OD may be prone to lateral buckling if not guided by a post or bore.
Store springs in a dry, low-humidity environment away from direct sunlight and corrosive chemicals. Keep them in their original packaging or in a labeled compartment tray to prevent tangling, especially for the smaller sizes. Avoid storing stainless steel springs in contact with carbon steel parts for extended periods, as iron particles can transfer and cause surface rust spots (tea staining) on the stainless surface.
Each variant in this listing represents a specific combination of outside diameter and free length. You can add multiple variants to your cart in a single order to get a mix of sizes. If you need a large quantity across many sizes for a production or maintenance kit, contact us — we may be able to assist with bulk or assortment packaging.
