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Finding the right compression spring for a repair or build project shouldn't mean compromising on fit. Whether you're a mechanical engineer sourcing replacement springs, a workshop technician maintaining industrial equipment, or a hands-on DIYer tackling a custom build, an ill-fitting spring causes premature failure, inconsistent force, and wasted time. These 305mm Mn steel compression springs are stocked across a wide range of wire and outer diameters so you can match the exact specification your application demands.
Each spring is formed from manganese steel wire, offering a balance of tensile strength and elasticity suited to cyclic load applications. The 305mm (approximately 12 inches) free length spans wire diameters from 0.3mm to 2mm and outer diameters from 3mm to 40mm, covering a broad spectrum of load ratings. Springs are available individually or in multi-piece quantities to suit both prototyping and production needs.
Typical use cases include compression spring replacement in mechanical assemblies, valve and actuator return mechanisms, jig and fixture clamping systems, and custom DIY fabrication projects requiring precise spring force. Long-tail applications such as "305mm long compression spring for industrial machinery" and "Mn steel pressure spring all sizes" are well served by this range.
305mm Free Length — Approximately 12 inches of uncompressed length, suitable for applications requiring extended travel or high deflection range.
Wide Size Range — Wire diameters from 0.3mm to 2mm paired with outer diameters from 3mm to 40mm, covering light-duty to medium-duty load requirements.
Manganese Steel Construction — Mn steel provides reliable tensile strength and fatigue resistance for cyclic compression applications.
Flexible Quantity Options — Available in 1 PCS, 2 PCS, or 20 PCS packs to suit prototyping, repair, or small-batch production needs.
Precision-Wound Coils — Consistent coil pitch and closed ends ensure stable seating and predictable load-deflection behavior across the full compression range.
Broad Application Compatibility — Fits standard spring pockets and guide rods sized to the selected outer diameter; suitable for valves, actuators, jigs, fixtures, and DIY mechanical builds.
| Free Length | 305mm (~12 in) |
|---|---|
| Wire Diameter Range | 0.3mm – 2mm |
| Outer Diameter Range | 3mm – 40mm |
| Material | Manganese Steel (Mn Steel) |
| Spring Type | Compression (Closed Ends) |
| Surface Finish | See variant options |
| Load Rating | See variant options |
| Spring Rate | See variant options |
| Quantity per Pack | 1 PCS / 2 PCS / 20 PCS |
| Coil Direction | Right-hand wound (standard) |
Select the wire diameter based on the load you need the spring to support — thicker wire (e.g., 1.5mm–2mm) handles heavier loads, while thinner wire (e.g., 0.3mm–0.6mm) suits lighter-duty or precision applications. The outer diameter must fit within your bore or spring pocket with a small clearance (typically 0.5mm–1mm per side). Check your housing dimensions before selecting a variant.
These springs are made from manganese steel (Mn steel), which offers a good balance of tensile strength, elasticity, and fatigue resistance. It is well suited for cyclic compression applications in mechanical assemblies, fixtures, and industrial equipment.
Manganese steel has moderate corrosion resistance. For environments with moisture, chemicals, or outdoor exposure, consider applying a protective coating after installation, or contact us to confirm if a treated finish variant is available for your size.
The free length is 305mm — this is the uncompressed length of the spring. The working (compressed) length depends on your application's travel requirement and the spring's solid height. Ensure your assembly allows sufficient travel without fully compressing the spring to solid height, which would cause coil bind and potential damage.
Manganese steel springs are generally suitable for standard operating temperatures. For elevated-temperature applications (above approximately 120°C / 250°F), the spring rate and fatigue life may be affected. Contact us to confirm suitability for your specific temperature range.
Spring rate depends on wire diameter, outer diameter, number of active coils, and material modulus. Because these springs are offered across a wide size range, specific spring rate data varies by variant. If you need a confirmed spring rate for an engineering application, please contact us with your selected Wire Dia × Outer Dia combination and we will provide the specification.
Yes — the 20 PCS pack contains the same spring as the single and double-piece options. The multi-pack is intended for production runs, batch repairs, or stocking purposes where multiple identical springs are needed at a lower per-unit cost.
