Cylinder Force Calculator Form
Example Data Table
| Pressure (bar) | Bore (mm) | Rod (mm) | Efficiency (%) | Extend Force (kN) | Retract Force (kN) |
|---|---|---|---|---|---|
| 120 | 50 | 20 | 90 | 21.21 | 17.81 |
| 160 | 80 | 36 | 92 | 73.99 | 59.01 |
| 210 | 100 | 45 | 95 | 156.69 | 124.96 |
Formula Used
Piston Area: Ap = πD² / 4
Rod Area: Ar = πd² / 4
Annular Area: Aa = Ap − Ar
Extend Force: Fextend = P × Ap × η
Retract Force: Fretract = P × Aa × η
Allowable Load: Fallowable = F / Safety Factor
Here, P is pressure, D is bore diameter, d is rod diameter, and η is mechanical efficiency as a decimal fraction.
Stroke length is used to estimate fluid volume moved and work performed during extension and retraction.
How to Use This Calculator
- Enter the system pressure and choose the matching pressure unit.
- Provide bore diameter, rod diameter, and their unit.
- Enter stroke length to estimate moved volume and work.
- Set mechanical efficiency to reflect seal drag and losses.
- Choose a safety factor for a more conservative allowable load.
- Optionally add a target load to check whether the cylinder meets it.
- Press the calculate button to show results above the form.
- Use the CSV or PDF buttons to export the result summary.
FAQs
1. What does cylinder force mean?
Cylinder force is the linear push or pull produced when fluid pressure acts on a piston area. Bore size, rod size, pressure, and efficiency determine the final usable force.
2. Why is retract force lower than extend force?
Retract force uses annular area, not full piston area. The rod occupies part of the piston face, reducing the effective area available during the return stroke.
3. Why should I include efficiency?
Efficiency accounts for real losses from seals, friction, alignment, and internal flow behavior. Using it produces a more practical force estimate than an ideal pressure-area calculation.
4. What safety factor should I choose?
Many designs start around 1.25 to 2.00, depending on duty, shock, uncertainty, and consequences of failure. Higher factors reduce allowable load and increase conservatism.
5. Does stroke length affect force?
Stroke length does not directly change theoretical force at a fixed pressure. It affects fluid volume moved and mechanical work delivered over the travel distance.
6. Can I use this for pneumatic cylinders?
Yes. The same pressure-area principle applies. Just enter the correct pressure, dimensions, and realistic efficiency. Pneumatic systems usually deliver lower forces than hydraulic systems.
7. What happens if rod diameter is close to bore diameter?
Retract area becomes very small, so retract force drops sharply. A large rod can improve stiffness, but it reduces available return force significantly.
8. Why export results as CSV or PDF?
CSV is useful for spreadsheets and batch review. PDF is useful for reports, approvals, and sharing a fixed summary with colleagues or clients.