Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 120mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke120 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 MI40X120SU
Delivering a robust 628.3 N of push force at 0.5 MPa, this double-acting round-body mini cylinder handles demanding actuation tasks. The stainless-steel barrel and Ø16 mm piston rod shrug off mild corrosion, making it highly suitable for damp or washdown environments where painted steel alternatives fail. Riveted construction keeps the unit compact, while fixed TPU bumper pads absorb the impact at stroke extremes. Because the bore exceeds Ø25, it is classified as a non-ISO-6432 round-body cylinder, yet it retains a highly practical footprint for its power class.
For real-world sizing, plan for a safe working load of roughly 377 N, which is about 60 percent of the 0.5 MPa push rating. Alternatively, you can expect it to lift a 32 kg part vertically when applying a sensible 2:1 safety margin. The U-style 90-degree rear cover provides flexible mounting orientation, and the 1/4" air port ensures high flow to maintain rapid cycling speeds between 30 and 800 mm/s. Since this SKU includes the -S magnet, it is fully primed for CMSG, DMSG or EMSG position sensing.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 120 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 MI40X120SU
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×120 | 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 MI40X120SU Is Used
Stamping Press Ejection
Uses the 628.3 N push force to knock heavy stamped metal parts out of a die, relying on the stainless build to resist cutting fluid splash.
Package Divert Arm
Leverages the 120 mm stroke and U-style 90-degree rear cover to pivot heavy cardboard cartons off a high-speed main conveyor belt.
Pallet Stopper Gate
Acts as a heavy-duty pneumatic stop for loaded pallets, safely halting 32 kg work-in-progress items without exceeding the 2:1 lift margin.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU the Right Cylinder?
When sizing this 40 mm bore actuator, compare it directly against its neighbours: a Ø32 bore provides 402.2 N of push at 0.5 MPa, whereas this Ø40 model jumps to 628.3 N. As the largest available frame in the series, there is no larger standard MI option, so if your application requires even more thrust, you will need to step up to a different cylinder family entirely. The 120 mm stroke is well within the 500 mm maximum standard limit, meaning no made-to-order lead times are required.
Keep in mind that a standard double-acting cylinder drifts when air pressure is lost or the directional valve is centred; the TPU bumpers only soften the end-of-stroke impact and do not function as a braking mechanism. If your machinery demands strict position holding under load, integrate an external rod lock or a pilot-operated check valve into your pneumatic circuit. The included -S magnet allows for drop-in installation of reed or electronic sensors.
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 MI40X120SU FAQ
At 0.5 MPa it provides 628.3 N push and 527.8 N pull. At 0.7 MPa it provides 879.6 N push and 738.9 N pull. The theoretical maximum force is 128.1 kgf at 1.0 MPa. This 40 mm bore unit features a 1/4" air port and a male M12x1.25 rod thread.
No, the piston will drift if air is lost or the valve is centred. The fixed TPU bumper pads only decelerate the rod near the stroke end and do not act as a lock. For vertical load holding, you must install an external rod lock or a pilot-operated check valve.
Authorized Export Seller
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.
Request a Quote for Airtac MI25~40 Stainless Steel Mini Cylinder MI40X120SU
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.