Inputs
Results are estimates. Efficiency depends on friction and seals; buckling is an approximate Euler check with a 3.5 safety factor. Critical applications need the manufacturer catalog and engineering approval.
Print / PDF
When you print, usage data (calculated values and the information you entered) is sent to Sistemay; your e-mail is not used for contact unless you give consent. Choose “Save as PDF” in the print dialog.Formulas and method
Cylinder force is effective area times pressure. The push (bore side) area is the full circle; the pull (rod side) area is the annulus with the rod area removed.
Speed is flow divided by area, so the smaller rod-side area makes the cylinder retract faster.
F [N] = p [bar] × A [mm²] × 0.1 × η
v [mm/s] = Q [L/min] × 16,667 ÷ A [mm²]
P [kW] = p [bar] × Q [L/min] ÷ 600
F_crit = π² × E × I ÷ (K × L)² (E = 210,000 N/mm², I = π d⁴ / 64)
Worked example
Example: Ø100 bore, Ø56 rod, 160 bar, 40 L/min, 90% efficiency → push ≈ 113 kN, pull ≈ 78 kN; extend speed ≈ 85 mm/s, retract speed ≈ 124 mm/s.
Practical tips
- If force is short, consider a larger bore before higher pressure; more pressure also loads the pump, hoses and seals.
- For long strokes size the rod by the buckling result; change the mounting if needed.
- Retract speed is higher than extend speed; check cushioning and valve capacity at high speed.
- Use a flow control valve for speed control and a check or counterbalance valve to hold loads.
Frequently asked questions
How is cylinder push force calculated?
Pressure (bar) × piston area (mm²) × 0.1 gives newtons. Multiply by efficiency for a realistic force.
Why is pull force lower?
The rod reduces the effective area on that side, so the same pressure gives less force.
What sets stroke speed?
Pump flow and effective area. Speed = flow ÷ area.
Why check buckling?
On long, slender rods the load can bend the rod before the material yields. The tool gives an approximate check.
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