Compression Spring Various Size 20-24mm Outer Dia. & 20-100mm Length Pressure

Measure the bore or spring pocket your spring must fit inside — the OD should be 1–2mm smaller than the bore for clearance. For free length, measure the uncompressed cavity depth and ensure the spring's free length is equal to or slightly longer than that dimension so it exerts force when installed. If you need a specific spring rate, calculate the required force at your working deflection and match it to the spring's rate (contact us for rate data on specific variants).

The load capacity depends on the specific OD and free length combination selected. Longer springs with the same wire and OD will have a lower spring rate (softer), while shorter springs will be stiffer. For precise load data on a specific variant, please contact us with your size selection and we can provide spring rate information.

These springs are made from carbon steel, which offers good mechanical properties but has limited inherent corrosion resistance. For outdoor, humid, or mildly corrosive environments, we recommend applying a light coat of machine oil or grease after installation. For highly corrosive environments, consider stainless steel springs instead. Indoor, dry, or lightly oiled applications are where carbon steel compression springs perform best.

The "3 x 20mm" designation means 3mm wire diameter and 20mm outer diameter. The inner diameter (ID) is approximately OD minus 2× wire diameter, so roughly 14mm for the 3×20mm variant. A guide rod should be no larger than ~13–13.5mm to allow free movement. For bore fit, the bore should be at least 21–22mm to give the spring clearance. Apply the same logic to other OD variants in this listing.

Yes. The closed and ground ends provide flat, stable seating that is well-suited for CNC fixture clamping returns and robotic actuator reset mechanisms. The consistent pitch winding ensures repeatable deflection behavior, which is important for applications where the spring must return a component to a precise position cycle after cycle.

If you are prototyping or testing a design, a single piece (1 Pcs) is the most economical starting point. For small production runs or to keep spares on hand, 3 or 5 Pcs packs offer a per-unit saving. For ongoing production, maintenance kits, or bulk stocking, the 10 Pcs pack provides the best per-unit value. All pack sizes ship the same spring — only the quantity differs.

The 150mm and 200mm free-length variants are available only in the 3×20mm OD size. These longer springs have a lower spring rate (they compress more easily per unit of force) and are suited for applications requiring a long travel range or a soft, progressive return force — such as long-stroke actuators or suspension-style mechanisms. Shorter variants (20–100mm) are stiffer relative to their length and are better for compact, high-force applications.