Spring Steel Compression Spring Pressure Coil 1.5mm Wire OD 18-25mm 10-150mm DIY

Measure the guide rod or bore your spring will seat in. The spring OD should be slightly smaller than the bore (typically 0.5–1mm clearance) or slightly larger than the guide rod (typically 0.3–0.8mm clearance). For free length, select a spring that is longer than your required compressed height plus your desired travel distance.

Spring rate varies by OD and free length combination. Shorter springs with smaller OD generally have a higher spring rate (stiffer), while longer springs with larger OD tend to be softer. Exact spring rate values are not published for each variant — if your application requires a specific rate, contact us to confirm before ordering.

These springs are made from spring steel, which offers good mechanical properties but has limited inherent corrosion resistance compared to stainless steel. For outdoor, humid, or chemically exposed environments, consider applying a light coating of oil or grease, or contact us to ask about alternative material options.

These springs are compatible with standard spring seats, guide rods, and counterbored pockets. They are commonly used in 3D printer bed leveling assemblies, DIY jigs, tool fixtures, robotics linkages, and light mechanical return mechanisms. Verify that your guide rod diameter is smaller than the spring ID and that your bore is larger than the spring OD.

Compression springs can be used under continuous preload, but operating at or near solid height (fully compressed) will cause set and reduce service life. As a general guideline, avoid compressing beyond 80% of the free length for continuous-duty applications. For intermittent or low-cycle use, higher compression ratios are acceptable.

When multiple OD sizes fit your bore, choose based on the spring rate you need. A larger OD spring with the same wire diameter and length will typically have a lower spring rate (softer). A smaller OD spring will be stiffer. If you need a specific force at a given deflection, calculate the required spring rate and select accordingly, or order a small sample set to test.

The size format follows Wire Diameter × Outer Diameter × Free Length. So "1.5mm X 20mm X 30mm" means: 1.5mm wire diameter, 20mm outer diameter, and 30mm free length. Use these three dimensions to match the spring to your application's guide rod, bore, and travel requirements.