Compression Spring 0.9mm Wire Dia 5/6/7/8mm Dia 8-50mm Length A2 Stainless Steel

Measure the bore or housing that will contain the spring. The spring's outer diameter should be 0.2–0.5 mm smaller than the bore to allow free movement without binding. For a shaft-guided spring, the inner diameter (OD minus twice the wire diameter) should clear the shaft by at least 0.2 mm. With a 0.9 mm wire, the inner diameters for these springs range from approximately 3.2 mm (5 mm OD) to 6.2 mm (8 mm OD).

Free length is the uncompressed length of the spring. Choose a free length that is longer than your required working length by enough to generate the desired spring force at the compressed position. As a starting point, a compression of 20–30% of free length is a common working range for light-duty applications. If you need a specific spring rate, contact us to confirm before ordering.

Yes. A2 (304) stainless steel provides good resistance to atmospheric corrosion, fresh water, and mild chemical exposure. It is not recommended for prolonged immersion in salt water or strong acids. For marine or highly corrosive environments, A4 (316) stainless steel would be a more appropriate choice.

These springs have closed and ground ends, meaning the last coil is wound tight against the adjacent coil and then ground flat. This creates a stable, perpendicular bearing surface that seats evenly against flat spring pockets or plunger faces, reducing side-load and improving alignment. Open-end springs lack this flat seat and are typically used where end geometry is less critical.

Yes. The small wire diameter (0.9 mm) and range of short free lengths (from 8 mm) make these springs well-suited for use in switches, connectors, instrument housings, and similar precision assemblies. A2 stainless steel is non-magnetic in its annealed state, which may be relevant for sensitive electronic environments — confirm magnetic requirements with your design specification.

For prototyping or one-off repairs, a pack of 10 is usually sufficient. For small-batch production runs or to maintain a working stock, packs of 50 or 100 offer a lower per-unit cost. If you are trialling multiple sizes, ordering a pack of 10 in each size lets you confirm fit and performance before committing to larger quantities.

All dimensions are metric. Wire diameter is 0.9 mm, outer diameters are 5, 6, 7, or 8 mm, and free lengths range from 8 mm to 50 mm. Approximate imperial equivalents: 5 mm ≈ 0.197 in, 8 mm ≈ 0.315 in, 50 mm ≈ 1.969 in.