Find the smallest ISO 6432 or ISO 15552 bore and matching rod for the required force, stroke and target speed.
Extension uses full piston area; retraction uses the annulus. Mountings, cushioning, buckling and manufacturer curves remain for detailed design.
Enter force, pressure, stroke and speed.
Determine standard bore, standard rod diameter and area ratio of a cylinder series from the required force, rather than picking a bore freehand afterwards.
Series (ISO 6432 small round cylinders or ISO 15552 profile cylinders), operating pressure, required force, extension/retraction direction, stroke, speed and efficiency.
Direction matters because the rod removes area during retraction. Stroke and speed also set required flow; a suitable bore can still move too slowly with an undersized valve.
Required piston area follows F = p*A*eta (gauge pressure, not absolute); the calculator then selects the smallest standard bore/rod combination in the chosen series whose area carries the load with margin, and additionally returns the area ratio phi = A/(A-Ar).
F = 500 N, p = 6 bar(g), extending, series ISO 15552: required area A = F/(p*eta) = 500/(6e5*0.85) ~= 981 mm^2, calculated bore diameter ~= 35.4 mm. The series has no 35 mm step; the next standard bore 40 mm with a 16 mm rod is selected, available force Fmax = 6e5*pi/4*0.04^2*0.85 ~= 641 N, force margin about 28%.
Sources and limits: ISO 6432:2008 and ISO 15552:2018 define bore/rod series, port and mounting dimensions for pneumatic cylinders with piston rod.
Determine standard bore, standard rod diameter and area ratio of a cylinder series from the required force, rather than picking a bore freehand afterwards.
ISO 6432 defines the bore series and mounting dimensions of small, single-rod round cylinders (8 to 25 mm bore in this implementation), ISO 15552 the larger series of profile cylinders with detachable, interchangeable mountings (32 to 320 mm bore). Both standards define only dimensions and connection sizes for interchangeability between manufacturers -- no force, speed or service-life rating. This calculator uses a force requirement only as a starting point to find the matching standard bore; the result is the orderable size with its area ratio, not primarily a force value as in the separate force/air-consumption calculator.
A = F / (p*eta)
F = p*A*eta (force check after standard-bore selection)phi = A / (A - Ar) = D^2 / (D^2 - d^2)Qn = V_chamber * (p+1.013)/1.013 * (v/stroke) * 60 (normalized flow)| Symbol / input | Meaning |
|---|---|
| F | Required external force (process load) the cylinder must safely move. |
| p | Operating gauge pressure in bar(g) at the cylinder port -- not the absolute pressure needed for the air-quantity calculation. |
| eta | Overall efficiency for seal friction and mechanical losses. |
| 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 series. |
| phi | Area ratio of the size. |
| Qn | Required normalized flow to reach the target speed over the chosen stroke. |
Series (ISO 6432 small round cylinders or ISO 15552 profile cylinders), operating pressure, required force, extension/retraction direction, stroke, speed and efficiency. Direction matters because the rod removes area during retraction. Stroke and speed also set required flow; a suitable bore can still move too slowly with an undersized valve.
Enter series (ISO 6432 or ISO 15552), operating gauge pressure, required force, direction, stroke, target speed and efficiency. The calculator returns the smallest matching standard bore with rod diameter and area ratio, plus -- as a check -- available force, force margin and required normalized flow.
F = 500 N, p = 6 bar(g), extending, series ISO 15552: required area A = F/(p*eta) = 500/(6e5*0.85) ~= 981 mm^2, calculated bore diameter ~= 35.4 mm. The series has no 35 mm step; the next standard bore 40 mm with a 16 mm rod is selected, available force Fmax = 6e5*pi/4*0.04^2*0.85 ~= 641 N, force margin about 28%.
The reported available force Fmax and force margin confirm that the selected standard bore carries the load -- but they are the outcome of the bore selection, not its target. Because bores come in discrete standard steps, a 0% force margin is the exception; typically there is a jump to the next step. The required normalized flow shows whether a standard valve can actually deliver the target speed -- a sufficiently large bore is useless if the valve or line cannot supply the needed airflow.
Pressure in bar(g), or bar(a) for the air quantity, force in N, stroke and diameter in millimetres, speed in mm/s, normalized flow in Nl/min.
Selecting a market-standard, interchangeable pneumatic cylinder size for a new design, checking whether an existing bore belongs to the matching ISO series, estimating the normalized flow needed for the target speed for valve and line sizing.
ISO 6432:2008 and ISO 15552:2018 define bore/rod series, port and mounting dimensions for pneumatic cylinders with piston rod.
Common mistake: Don't use the exact calculated, non-standard bore -- market-standard cylinders come only in certain standard sizes. Don't confuse operating gauge pressure with the absolute pressure needed for the air-quantity calculation: cylinder force follows from gauge pressure against the atmosphere-vented opposite side, while normalized flow follows from absolute pressure. Don't label ISO 6432 as generically "short-stroke" -- the standard defines a bore series of small round cylinders, not a stroke limit.
ISO 6432 standardizes a bore series of small, compact round cylinders; ISO 15552 the larger series of profile cylinders with detachable, interchangeable mountings. Both define dimensions and connection sizes, not a stroke limit or force rating.
In this implementation, ISO 6432 from 8 to 25 mm and ISO 15552 from 32 to 320 mm bore -- the complete standard series can include additional intermediate or edge sizes depending on the manufacturer.
The standards themselves do not set a single maximum pressure; they define dimensions. The permissible operating pressure follows from the specific manufacturer product's rating and is typically around 10 to 16 bar for standard pneumatic cylinders.
Bore and rod diameter, the resulting area ratio, and port and mounting dimensions -- not seal system, material or cushioning design.
Only dimensionally and at the standardized connection sizes. Seal system, end-of-stroke cushioning, material and permissible side load can differ between manufacturers despite an identical standard bore.
Retraction only has the annular area, reduced by the piston-rod cross-section, available, while extension force relies on the full piston area. The area ratio phi states the factor by which force and speed change as a result.
Cylinder force follows from gauge pressure (difference to atmosphere), since the opposite side vents to atmosphere. Absolute pressure is needed only to convert to normalized flow (air quantity at reference conditions).
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.