Airtec NAEE Normally-Extended Pneumatic Cylinders
Airtec Series NAEE pneumatic cylinders are single-acting ISO 21287 compact actuators designed with the piston rod extended in its normal rest position. Compressed air retracts the piston rod against the internal spring, and when pneumatic pressure is removed the spring returns the rod to the extended position.
This operating principle makes NAEE particularly useful for machine stops, locating pins, locking mechanisms, retainers and other short-stroke functions where the actuator needs to return automatically to an extended position when the pneumatic signal is removed.
For conventional double-acting compact movement, compare Airtec NAD pneumatic cylinders. Where piston-rod rotation also needs to be controlled, see Airtec NADA pneumatic cylinders. You can also browse the complete Airtec pneumatic cylinder range.
Spring Extended When the Air Is Off
The most important characteristic of NAEE is not simply that it is single acting. It is the direction in which the internal spring moves the piston rod.
With no pressure applied, an NAEE pneumatic cylinder sits with the rod extended. Applying compressed air retracts the piston. Removing that pressure allows the spring to drive the rod back outward.
This can be valuable when the extended position represents the required default state of the machine, for example where a stop should remain engaged until pneumatic pressure is deliberately applied to release it.
Airtec NAEE Technical Specification
| Manufacturer |
AIRTEC |
| Series |
NAEE |
| Product Category |
Normally-extended compact pneumatic cylinders |
| Dimensional Standard |
ISO 21287 |
| Operation |
Single acting |
| Rest Position |
Piston rod extended |
| Pneumatic Movement |
Air pressure retracts the piston rod |
| Return Movement |
Spring extends the piston rod |
| Bore Range |
20 to 100 mm across the verified NAEE range |
| Standard Short Strokes |
5, 10, 15, 20 and 25 mm |
| Position Detection |
Magnetic piston |
| Head and Foot |
Aluminium |
| Cylinder Tube |
Anodised aluminium |
| Piston Rod |
Stainless steel |
| Seal Materials |
NBR / PUR |
| Maximum Operating Pressure |
10 bar |
| Temperature Range |
-20°C to +80°C |
| Cylinder Switch Types |
Airtec D and A series |
| Rod Thread Options |
Female internal thread or -AG external male thread |
Short-Stroke Machine Functions
NAEE is concentrated around short movements rather than long linear travel. Verified products are available in 5, 10, 15, 20 and 25 mm strokes, making the range particularly suitable where the pneumatic cylinder only needs enough movement to engage or release a mechanical function.
Typical applications include pallet stops, locating pins, component retainers, latches, machine interlocks and compact fixture movements.
NAEE Bore Sizes
The normally-extended principle is available across a broad range of bore sizes, allowing the required spring-return behaviour to be combined with different pneumatic force levels.
Internal or External Piston-Rod Thread
Standard NAEE pneumatic cylinders use an internal female piston-rod thread. Airtec also provides -AG versions with an external male thread.
For example, NAEE 20/20 uses an M6 internal rod thread, while NAEE 20/20-AG uses an M8 external rod thread. The operating principle remains the same, but the mechanical connection to the machine is different.
Always preserve the complete MPN when replacing an installed pneumatic cylinder because bore and stroke alone do not identify the rod-end configuration.
Magnetic Position Detection
NAEE pneumatic cylinders incorporate a magnetic piston and can be used with compatible Airtec D- and A-series cylinder switches.
This is particularly useful on stops and locking functions because the machine controller can confirm whether the spring has returned the pneumatic cylinder to its normal extended position before another stage of the process begins.
NAEE or NAD?
| Airtec Series |
Operation |
Machine Behaviour |
| NAD |
Double acting |
Compressed air powers both extension and retraction |
| NAEE |
Single acting |
Air retracts the rod and the spring returns it to the extended position |
Although both use ISO 21287 compact dimensions, changing from NAEE to NAD changes the pneumatic circuit and removes the spring-defined extended rest position.
NAEE or NADA?
Airtec NADA solves a different problem. NADA is double acting and uses a non-rotating piston rod to maintain tooling orientation. NAEE is selected because of its single-acting, spring-extended behaviour.
The correct choice therefore depends on the function required by the machine rather than simply matching the ISO standard and installation dimensions.
Why the Rest Position Matters During Replacement
If an existing pneumatic cylinder is marked NAEE, the spring-extended arrangement may be an intentional part of the machine design.
Replacing it with a normally-retracted or double-acting pneumatic cylinder can reverse the default position or alter what happens when air pressure is lost. The complete operating principle should therefore be confirmed before selecting an alternative.
Example: Airtec NAEE 32/25-AG
NAEE 32/25-AG is a 32 mm bore × 25 mm stroke, single-acting ISO 21287 pneumatic cylinder with a G1/8 pneumatic port and external piston-rod thread. It is one of the NAEE products already available through Cylinder Warehouse.
Browse the 32 mm bore pneumatic cylinder range where a dimensional or cross-brand comparison is required.
Airtec NAEE Selection Questions
What does normally extended mean?
It means the piston rod is extended when no compressed air is applied. Pneumatic pressure retracts the rod, and the internal spring extends it again when that pressure is removed.
Is Airtec NAEE definitely ISO 21287?
Yes. Verified Airtec NAEE product data identifies these products as single-acting ISO 21287 compact pneumatic cylinders.
What does -AG mean?
The -AG suffix identifies the version with an external male piston-rod thread. Standard versions use an internal female thread.
Can I replace an NAEE with a normal single-acting pneumatic cylinder?
Only if the replacement has the same operating direction. A single-acting pneumatic cylinder can be spring retracted or spring extended, so merely matching the acting type is not sufficient.
Why would I use NAEE for a machine stop?
The spring can keep the stop extended when pneumatic pressure is absent. Applying air then retracts it when the control system wants the machine movement to proceed.
Where can I compare other ISO 21287 pneumatic cylinders?
Browse ISO 21287 compact pneumatic cylinders, compare Airtec NAD and Airtec NADA, or return to the main Airtec pneumatic cylinder range.
