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Pneumatic Cylinders

Pneumatic cylinders are the primary actuators in compressed-air-driven automation, converting air pressure into linear force and motion to clamp workpieces, transfer parts, and drive machine sequences. A pneumatic air cylinder's function in an installed machine is defined by its bore and stroke dimensions and its mounting configuration, making correct part identification essential before sourcing a replacement. PLC Direct stocks pneumatic cylinder hardware from Festo for replacement and maintenance in existing installed systems.

Where Are Pneumatic Cylinders Used in Industrial Environments?

Pneumatic cylinders perform the physical work of machine automation, applying linear force to clamps, stops, gates, transfer mechanisms, and tooling directly at each action point in a machine sequence. Replacement is sourced when a specific cylinder reaches the end of service life due to seal wear or mechanical damage, and the replacement must match the bore, stroke, and mounting configuration of the installed unit to fit the existing machine structure.

Facilities and operations that depend on pneumatic cylinders include:

Metal fabrication and stamping operations using pneumatic cylinders to actuate part clamps, stops, and ejectors in press tooling.

Pick-and-place automation systems where pneumatic cylinders drive grippers, slides, and indexing mechanisms in assembly sequences.

Plastics injection molding facilities using pneumatic cylinders for gate actuation, part ejection, and core pull mechanisms.

Semiconductor and electronics manufacturing, where pneumatic cylinders handle wafer positioning and precision part placement.

Pharmaceutical packaging lines where pneumatic cylinders actuate fill heads, cap applicators, and carton-sealing mechanisms.

When a cylinder fails in an installed machine, sourcing a replacement that matches the bore, stroke, and mounting configuration ensures a direct fit without structural modification.

Which Brands of Pneumatic Cylinders Does PLC Direct Stock?

PLC Direct stocks Festo pneumatic cylinders for replacement and maintenance in existing installed systems.

Festo DNC series: Standard ISO double-acting pneumatic cylinders for general industrial automation and machine building applications.

Festo DNCI series: Standard ISO cylinders with integrated piston position sensing for applications requiring control system feedback on cylinder stroke position.

Festo DSBC series: Updated ISO standard cylinders with refined mounting options for replacement in installed machine building applications.

Festo DSNU series: Round body compact cylinders for applications where space constraints require a smaller cylinder footprint without reducing stroke capability.

All pneumatic cylinder hardware in this collection is available as Sealed Surplus, Never Used Surplus, or Used/Refurbished, subject to inventory.

What Should You Know Before Ordering Pneumatic Cylinders?

Hardware condition options: Pneumatic cylinders are supplied as Sealed Surplus, Never Used Surplus, or Used/Refurbished. Sealed Surplus units provide new seals and an unused bore surface. Used/Refurbished cylinders have been inspected, tested, and restored to working condition, and are available for applications where immediate replacement is needed pending a preferred-condition unit.

Compatibility and part identification: Pneumatic cylinders are specified by bore size, stroke length, mounting style, and port connection size. Before ordering a replacement pneumatic air cylinder, confirm all four parameters from the installed unit's part number, as a mismatch in any one of them requires either a machine modification or a non-standard mounting arrangement to fit the existing installation.

Warranty: All pneumatic air cylinder hardware purchased from PLC Direct carries a standard 1-year PLC Direct warranty, not an OEM warranty, covering defects and functionality, applicable to all condition grades. This warranty is issued by PLC Direct as an independent supplier. PLC Direct supplies pneumatic cylinder hardware for replacement and maintenance purposes and does not provide system design, programming, or integration services.

Frequently Asked Questions

Cushioning slows the piston as it approaches the end of its stroke by restricting exhaust flow just before the end cap, reducing impact force at the end position. It is particularly important for cylinders moving heavy loads at high speeds, where the impact force without cushioning would cause noise, vibration, and accelerated wear of the end caps and rod seals.

A piston rod cylinder transmits force through a rod extending from the piston through the front end cap, used where the load connects directly to the rod. A rodless cylinder transmits piston motion to an external carriage along the cylinder body rather than through an end cap, allowing longer strokes in installations with limited available length.

Bore size is the internal diameter of the cylinder barrel, which determines the piston face area that compressed air acts against to generate thrust force. A larger bore produces greater force at the same supply pressure, so bore selection is driven by the load requirements at the machine function point, not by the physical space available for the cylinder.

A cylinder with integrated position sensing uses magnetic sensors mounted along the cylinder body to detect a magnet embedded in the piston, providing a discrete signal to the control system when the piston reaches a set position. This confirms stroke completion without a separate external proximity sensor mounted to the machine frame, reducing the number of components installed around the cylinder.

ISO-standardized cylinders define mounting dimensions, port positions, and end-cap interface geometry, allowing cylinders from different manufacturers within the same ISO series to be installed in the same machine position. A cylinder in an installed machine can often be replaced with an equivalent unit from another manufacturer in the same ISO series, provided the bore and stroke match, giving greater sourcing flexibility when an exact part number is unavailable.