Micro Compression Springs Wire Diameter 0.7mm Spring Steel Pressure Spring DIY

Measure the inner diameter of your spring pocket or bore. The spring OD should be slightly smaller than the pocket ID to allow free movement — typically 0.2–0.5mm clearance. If the spring runs on a guide pin, the pin diameter should be smaller than the spring's inner diameter (OD minus twice the wire diameter, so approximately OD − 1.4mm for this 0.7mm wire gauge).

The free length should be long enough so that at your maximum working deflection the spring still has remaining travel — never compress a spring to solid length in normal operation. A common guideline is to keep working deflection below 30–40% of the free length for light-duty applications. Measure your available pocket depth and required pre-load travel to determine the minimum free length needed.

Yes. The small wire diameter and compact OD range (starting at 4mm) make these springs well-suited for push-button contacts, battery terminals, pogo-pin assemblies, and other PCB-adjacent mechanisms where space is limited. Spring steel is not corrosion-resistant in humid environments, so consider a light protective coating if the application involves moisture exposure.

With a 0.7mm wire diameter, these are light-duty micro springs. They are designed for low-force applications such as button returns, pen mechanisms, and small actuator pre-loads. For higher-force requirements in the same OD range, a heavier wire gauge (e.g., 1.0mm or 1.2mm) would be needed. The spring rate (force per mm of deflection) increases with OD and decreases with free length for a given wire diameter.

Spring steel can oxidize in humid or wet environments. For indoor, dry applications these springs perform reliably without additional treatment. For outdoor or moisture-exposed use, applying a light machine oil or selecting a stainless steel spring alternative is recommended to extend service life.

The 10-piece pack is the better value for prototyping, small-batch production, or when you want spares on hand. The 5-piece pack suits single-unit repairs or situations where you need a specific size in a small quantity. Note that longer lengths (60mm and above) are only available in the 5-piece pack for most OD sizes.

Yes, nesting two springs of different ODs concentrically is a common technique to increase force in a limited space. Ensure the inner spring OD is smaller than the outer spring ID (outer spring ID ≈ OD − 1.4mm) with at least 0.5mm clearance between the two springs to prevent coil-to-coil contact during compression.