Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 290mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke290 mm
- Port size1/4"
- Acting typeDouble acting
- Rod threadM12×1.25
- CushionFixed TPU bumper pads
- No minimum order. A single piece can be ordered.
- Ready in 3–5 business days. That is the time we take to process the order and hand it to the carrier. Transit time after that depends on the destination.
About the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU
Delivering 628.3 N of push force at 0.5 MPa, this double-acting stainless-steel round-body mini cylinder handles substantial actuation tasks. The Ø40 mm bore operates on a 1/4" port with a 290 mm stroke, while the U-type back cover provides a 90-degree port orientation for tight machinery layouts. Its riveted stainless barrel and rod resist mild corrosion, making it highly suitable for damp washdown environments where painted bodies fail.
When sizing this actuator, plan for a real working load of roughly 377 N to maintain a safe margin. This translates to lifting about 32 kg vertically, letting you match the cylinder directly to heavy part weights. The built-in piston magnet (-S) supports CMSG, DMSG and EMSG switches for position sensing, and fixed TPU bumper pads absorb the impact at stroke ends without adjustable cushioning.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 290 mm |
| Acting type | Double acting |
| Port size | 1/4" |
| Rod thread | M12×1.25 |
| Fluid | Air (filtered by 40µm element) |
|---|---|
| Operating pressure | 0.15 – 1.0 MPa |
| Proof pressure | 1.5 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Fixed TPU bumper pads |
| Max standard stroke | Up to 500 mm |
Specifications follow the official AirTAC MI/MIC (ISO 6432) datasheet. Barrel & rod: stainless steel (round-body, riveted construction). Thread options: PT (blank) / G. Note: the Ø40 bore is a larger, non-ISO-6432 size.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | 739 N |
| Max (@1.0 MPa) | 128 kgf | |
Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
Model Code: Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×290 | Stroke length in mm. |
| -S | Optional built-in magnet for CMSG / DMSG / EMSG sensors. |
MI-family variants: MI / MIC (double acting ±cushion), MSI / MTI (single acting push / pull), MID / MICD (double rod ±cushion), MIJ / MICJ (adjustable stroke ±cushion). Back covers CA / U / R / CM. Mounting LB / FA / SDB / TC.
Where the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU Is Used
Heavy Package Diverting
Pushes heavy cartons weighing up to 32 kg across sorting lanes on packaging lines using its 628.3 N push force at 0.5 MPa.
Washdown Gate Actuation
Operates stainless-steel machine guards in food processing plants where the riveted round-body construction resists moisture and mild corrosion.
Pallet Component Indexing
Moves heavy pallet fixtures or chassis components over its 290 mm stroke, using the 90-degree U back cover to keep pneumatic hoses neatly routed.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU the Right Cylinder?
As the largest bore in the MI family, the Ø40 provides maximum thrust with no larger standard size available. If your application only needs 402.2 N of push at 0.5 MPa, stepping down to the Ø32 bore saves space and air consumption. Because this 290 mm stroke is relatively long, ensure your mounting configuration—such as an LB foot or FA flange—prevents rod side-loading and bending. The U back cover simplifies plumbing by turning the air supply 90 degrees.
Remember that the fixed TPU bumpers only decelerate the piston near the end of travel; they do not function as a lock. If air pressure drops or the valve is centred, the piston will drift and drop the load. To safely suspend a weight, integrate an external rod lock or a pilot-operated check valve into your pneumatic circuit.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT / G)
- ✓ Magnet (-S) for sensors?
- ✓ Back cover (CA/U/R/CM) & mount (LB/FA/SDB/TC)
Installation & Maintenance Notes
- check Use clean air filtered to 40µm or finer.
- check Keep within 0.15 – 1.0 MPa operating pressure.
- check Avoid side load on the piston rod.
- check Do not dismantle the riveted front/back covers.
- check Use correct back cover (CA/U/R/CM) & mount (LB/FA/SDB/TC).
- check Installation by qualified personnel per AirTAC docs.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X290SU FAQ
This double-acting cylinder delivers 628.3 N push and 527.8 N pull at 0.5 MPa, increasing to 879.6 N push and 738.9 N pull at 0.7 MPa. The theoretical maximum force is 128.1 kgf at 1.0 MPa. It uses a 1/4" air port and a Ø16 mm piston rod with an M12x1.25 male thread.
Yes to sensors, no to adjustable cushions. The -S suffix means it has a built-in magnet for CMSG, DMSG and EMSG reed or electronic switches. For deceleration, it relies on fixed TPU bumper pads at both ends. If you need adjustable air cushioning for high-speed cycles, look at the MIC variant instead.
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Genuine AirTAC parts produced by AirTAC factory.
1-Year Warranty
Covers non-human-caused product damage.
Fast Dispatch
Standard models are processed and dispatched in 3-5 business days.
Fast Reply
Most inquiries answered within 7-8 hours.
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