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Engineers and makers working on mechanical assemblies, CNC fixtures, or industrial automation often struggle to find compression springs that combine consistent load ratings with precise dimensional tolerances. These 400mm long compression springs are designed for builders who need dependable elastic return force across a wide range of outer diameters and wire gauges — without compromising on dimensional accuracy.
Each spring is a single-piece coiled compression spring, manufactured from spring steel wire. Wire diameters range from 2.3 mm to 22 mm (approx. 0.09 in to 0.87 in), and outer diameters span 16 mm to 120 mm (approx. 0.63 in to 4.72 in). Free length is 400 mm (approx. 15.75 in). Ends are typically closed and ground for stable seating.
Typical use cases include CNC router Z-axis return mechanisms, robotic arm joint preloading, industrial press tooling, and DIY mechanical linkage assemblies requiring consistent compression spring force over long travel distances.
Outer diameters from 16 mm to 120 mm and wire diameters from 2.3 mm to 22 mm cover a broad spectrum of load and travel requirements in a single product line.
The 400 mm (15.75 in) free length provides extended travel stroke, making these springs well-suited for long-travel compression applications in automation and tooling.
Wound from spring steel wire for consistent elastic return, fatigue resistance, and dimensional stability under repeated compression cycles.
Closed and ground end coils provide flat, stable seating surfaces that reduce lateral deflection and improve alignment on guide rods and spring seats.
Uniform coil pitch and wire diameter tolerances deliver repeatable spring rates, critical for precision mechanical assemblies and automated systems.
Applicable across CNC machines, robotic joints, industrial presses, die sets, and DIY mechanical projects requiring long-stroke compression spring force.
| Spring Type | Compression Spring |
|---|---|
| Free Length | 400 mm (15.75 in) |
| Outer Diameter Range | 16 mm – 120 mm (0.63 in – 4.72 in) |
| Wire Diameter Range | 2.3 mm – 22 mm (0.09 in – 0.87 in) |
| Material | Spring Steel |
| End Type | Closed & Ground |
| Coil Direction | Right-hand (standard) |
| Surface Finish | See variant options |
| Spring Rate | See variant options |
| Max Load Capacity | See variant options |
| Quantity per Order | 1 pc (per variant) |
Measure the inner diameter of your spring housing or the outer diameter of your guide rod. The spring's outer diameter should be slightly smaller than the housing bore (typically 1–2 mm clearance) and larger than the guide rod (typically 1–2 mm clearance on each side). Select the variant whose outer diameter fits within those tolerances.
Wire diameter directly affects spring rate and load capacity. Larger wire diameters (e.g., 12 mm, 16 mm, 22 mm) produce stiffer springs with higher load ratings, suitable for industrial presses and heavy tooling. Smaller wire diameters (e.g., 2.3 mm, 2.6 mm) are appropriate for lighter-duty return mechanisms and low-load automation fixtures.
These springs are made from spring steel, which offers good mechanical properties but moderate corrosion resistance. For environments with moisture or mild chemical exposure, consider applying a light coat of machine oil or grease after installation. For highly corrosive environments, contact us to confirm suitability.
Yes. The closed and ground ends provide flat seating surfaces compatible with standard spring seats and guide rod assemblies. Verify that your guide rod diameter is smaller than the spring's inner diameter (outer diameter minus twice the wire diameter) to ensure proper fit and prevent binding.
Yes. These 400mm compression springs are well-suited for CNC Z-axis return mechanisms, robotic joint preloading, and automated tooling fixtures. Their consistent coil pitch and spring steel construction support repeatable performance across many compression cycles.
Start by identifying your required travel (deflection) and the load at that deflection. Divide the load by the deflection to estimate the required spring rate (N/mm or lbf/in). Then select a wire diameter and outer diameter combination that meets that rate. If you need assistance matching specifications, contact us with your load and travel requirements.
Free length (400 mm) is the spring's uncompressed length. Working length is the compressed length during operation. The difference between free length and working length is the deflection (travel). Ensure your assembly provides enough space for the full free length and that the spring does not reach solid height (coil bind) during maximum compression.
