Cylinder force from bore and pressure
The force of a pneumatic cylinder comes from piston area and working pressure. Once you know bore, pressure and direction of travel, you size the drive and valve with confidence instead of guessing. This guide walks through the formula, the role of the rod and a sensible safety factor step by step.
View pneumatic cylindersHow do I calculate force from bore and pressure?
Theoretical force is pressure times piston area: F = p x A. The area follows from the bore d via A = pi/4 x d². Convert the pressure to pascal (1 bar = 100000 Pa) and the area to square metres, and the force comes out in newtons. A 32 mm bore has about 8.04 cm² of piston area and delivers roughly 483 N of push force at 6 bar.
Why is the pull force smaller than the push force?
On extension the pressure acts on the full piston area, on retraction only on the annular area, because the rod covers part of it. The pull force is therefore always smaller. The rod diameter is decisive: A_ring = pi/4 x (d² - d_rod²). For a 32 mm bore with a 12 mm rod the retract force drops by about 14 percent.
- For pulling and lifting loads, base sizing on the smaller annular area.
- Double-acting cylinders give force in both directions, but unequal in size.
- On a long stroke check the rod against buckling, not just the force.
What safety factor should I plan for?
The calculated force is a theoretical value. Friction in seals and guide, back pressure on the exhaust side and dynamic loads eat into the usable force. Plan a safety factor of 1.3 to 2 so the cylinder still pushes reliably under real conditions. Flow control valves and end-position cushioning handle smooth acceleration and defined braking.
A regulator holds the working pressure constant and the force repeatable.
Pressure regulator guideFrequently asked questions
How do I get the piston area from the bore?
Piston area is A = pi/4 times bore squared. A 32 mm bore gives about 8.04 cm². Multiplied by the working pressure you get the theoretical push force, so about 483 N at 6 bar.
Why does my cylinder push less than calculated?
The formula value is ideal. Seal friction, back pressure on the exhaust side and dynamic loads lower the usable force by often 10 to 20 percent. That is why you plan a safety factor of 1.3 to 2.
Is the force the same on extend and retract?
No. On retract the rod covers part of the area, so only the annular area acts. Depending on rod diameter the pull force is therefore about 10 to 30 percent smaller than the push force.
Size the right pneumatic cylinder
Our pneumatics specialists help with bore, pressure and safety factor for your load.
Clear formula
Force from piston area and pressure explained transparently.
Push and pull
Annular area and rod correctly accounted for.
Safety reserve
Sensible factor against friction and back pressure.
Expert advice
Pneumatics specialists support your sizing.