What this calculator does
A conical or tower spring has a changing diameter, so the coils can nest inside one another when compressed. That gives a very short solid height and good lateral stability. The calculator handles constant and variable pitch, reports the load–deflection curve and checks for coil interference.
Inputs and outputs
Inputs
- Small and large mean diameter
- Wire diameter
- Active coils
- Pitch schedule
- Free length
- Working load
Results
- Rate in the linear region
- Deflection and stress
- Solid and nested height
- Stability check
- Load–deflection curve
Typical applications
- Battery contacts
- Clutch assemblies
- Valve retainers
- Compact mechanisms
- Vibration isolation
Design notes
Keep the large end stable against the housing and confirm that nested coils do not rub. A tower spring is less linear than a cylinder, so specify the working point rather than only the free length.
The interactive calculator interface is currently in Chinese. Enter your values there, or send us the load, travel and space constraints and our engineers will return a checked calculation sheet in English.
Frequently asked questions
Why choose a conical spring?
A conical spring can compress into a height close to one wire diameter because the coils nest. It also has a wider base, which improves lateral stability in a bore.
Is the spring rate constant?
No. The rate rises as the larger coils become inactive and the spring progressively stiffens. The curve in the calculator shows the effective rate at each deflection.
Can you produce variable pitch?
Yes. Pitch can change along the cone so the spring closes in a controlled sequence. Provide the load at two or three positions and we will define the pitch schedule.
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Need this spring manufactured?
Send a drawing, a sample or the parameters from this calculator. We will review manufacturability and reply with a quote and a sample lead time.