Find the smallest bore and rod from ISO 6020-1 (160 bar) or ISO 6022 (250 bar) for the required force and speed.
The selected nominal pressure class limits operating pressure. Buckling, side loads, seals, ports and pressure peaks require separate checks.
Enter force, pressure, stroke and speed.
Determine standard bore, standard rod diameter, area ratio and nominal pressure class of a cylinder series from the required force.
Series with pressure class (ISO 6020-1 up to 160 bar or ISO 6022 up to 250 bar), operating pressure, required force, extension/retraction, stroke, speed and efficiency.
The standard series provides interchangeable dimensions, not automatic project capacity. Pressure, speed and direction must be considered together; annular area lowers retraction force and raises speed at equal flow.
F = p*A*eta sets the required piston area; the calculator selects the smallest bore/rod combination of the ISO 3320 series whose area carries the load with margin, provided operating pressure does not exceed the series' nominal pressure class.
F = 30,000 N, p = 160 bar, extending, series ISO 6020-1: A = F/(p*eta) = 30,000/(160e5*0.9) ~= 2083 mm^2, calculated bore diameter ~= 51.5 mm. The next standard bore 63 mm with a 32 mm rod is selected, Fmax = 160e5*pi/4*0.063^2*0.9 ~= 44,900 N, area ratio phi ~= 1.35.
Sources and limits: ISO 3320:2013 defines bore/rod series and area ratios; ISO 6020-1 (160 bar) and ISO 6022 (250 bar) add mounting dimensions per pressure class.
Determine standard bore, standard rod diameter, area ratio and nominal pressure class of a cylinder series from the required force.
ISO 3320 defines bore and rod diameter series and the resulting area ratios for hydraulic cylinders so cylinders from different manufacturers stay interchangeable -- it makes no statement about the load capacity, buckling safety or service life of an actual cylinder. ISO 6020-1 and ISO 6022 add the mounting and fixing dimensions for the 160 bar and 250 bar series respectively. This calculator uses a force requirement only as a starting point to find the matching standard bore -- unlike a plain force calculator, the result is the orderable cylinder size with its area ratio and pressure class, not primarily a force value.
A = F / (p*eta)
F = p*A*eta (force check after standard-bore selection)phi = A / (A - Ar) = D^2 / (D^2 - d^2)Q = A*v (required flow)| Symbol / input | Meaning |
|---|---|
| F | Required external force the cylinder must provide. |
| p | Operating pressure in bar; must stay below the nominal pressure class of the chosen series. |
| eta | Mechanical efficiency for seal and guide friction. |
| A | Effective piston area; full piston area when extending, annular area when retracting. |
| D, d | Standard bore and standard rod diameter of the selected ISO 3320 combination. |
| phi | Area ratio of the size, determines the speed and force ratio between extending and retracting. |
| Q | Required flow from effective area and target speed. |
Series with pressure class (ISO 6020-1 up to 160 bar or ISO 6022 up to 250 bar), operating pressure, required force, extension/retraction, stroke, speed and efficiency. The standard series provides interchangeable dimensions, not automatic project capacity. Pressure, speed and direction must be considered together; annular area lowers retraction force and raises speed at equal flow.
Select the series with pressure class, enter operating pressure, required force, direction, stroke, target speed and efficiency. The calculator returns the smallest matching standard bore with rod diameter, area ratio, and -- as a check -- the actually available force and force margin.
F = 30,000 N, p = 160 bar, extending, series ISO 6020-1: A = F/(p*eta) = 30,000/(160e5*0.9) ~= 2083 mm^2, calculated bore diameter ~= 51.5 mm. The next standard bore 63 mm with a 32 mm rod is selected, Fmax = 160e5*pi/4*0.063^2*0.9 ~= 44,900 N, area ratio phi ~= 1.35.
The area ratio phi = A/(A-Ar) describes how much faster the cylinder retracts than extends (at equal flow), or equivalently how much retraction force falls short of extension force. A phi near 2 means a relatively thick piston rod and a large difference between extend and retract behaviour; a phi near 1 means a thin rod with nearly identical behaviour in both directions. The reported force margin is a check value, not a design target -- with a clearly excessive margin it is worth checking the next smaller standard bore, if available.
Pressure in bar, force in N, stroke and diameter in millimetres, speed in mm/s, area ratio dimensionless.
Selecting a market-standard, interchangeable cylinder size for a new design, matching an existing cylinder bore to its standard rod size, determining the area ratio for a differential (regenerative) circuit.
ISO 3320:2013 defines bore/rod series and area ratios; ISO 6020-1 (160 bar) and ISO 6022 (250 bar) add mounting dimensions per pressure class.
Common mistake: Don't check force requirements alone while ignoring speed -- at limited flow, a larger bore for more force automatically forces lower speed or a larger pump flow. Don't mistake the standard bore for a functional approval: ISO 3320 governs only dimensions and interchangeability, not buckling safety, seal suitability or manufacturer sign-off for the actual load case.
ISO 3320 defines the bore and rod diameter series and the resulting area ratios. ISO 6020-1 adds mounting and fixing dimensions for the 160 bar series, ISO 6022 the corresponding dimensions for the heavier-duty 250 bar series.
Both series use their own bore/rod series and mounting dimensions per ISO 6020-1 and ISO 6022 respectively; the 250 bar series is designed for higher nominal pressure and correspondingly higher force per bore, not simply a pressure-rated version of the same dimensions.
Bore diameter, piston-rod diameter and the resulting area ratios (ISO 3320), plus port, mounting and installation dimensions (ISO 6020-1/6022) -- not material, seal system or permissible load cases.
No. The same bore and port do not automatically mean the same load capacity or service life -- material, seal system, guide length and manufacturer approval differ between suppliers despite identical standard dimensions.
It is already fixed by the chosen standard bore as a bore/rod pairing of the ISO 3320 series, not freely selectable. For an application with high buckling risk, a size with a thicker rod (smaller phi) can make sense if the series offers such a pairing.
Yes. This selection returns only bore and rod diameter from the force requirement; the buckling safety of the extended rod under long stroke and compressive load must be verified separately with the buckling calculator.
All main influencing quantities are shown as inputs or intermediate results. Check factors, material data and boundary conditions against the complete standard.
The local standards provide terminology and series values. This tool deliberately identifies its simplified scope and does not claim conformity.
Use the result as a starting point for selection and plausibility; then verify manufacturer data, load spectra and safety requirements.