Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125U
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125U is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 125mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke125 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 MI40X125U
Delivering 628.3 N of push force at 0.5 MPa, this double-acting round-body mini cylinder handles heavy-duty actuation where smaller bores stall. The Ø40 mm stainless-steel barrel and piston rod shrug off mild corrosion, giving it a real edge over painted alternatives in damp or washdown environments. It is a riveted construction, not a tie-rod design, keeping the body compact.
The integrated fixed TPU bumper pads absorb stroke-end impact to protect the mechanism, though they decelerate rather than provide adjustable cushioning. Because this specific SKU lacks the -S magnet, it cannot accept CMSG, DMSG or EMSG position switches. For sizing your payload, plan for a safe working load of roughly 377 N, which equates to lifting about 32 kg vertically with a 2:1 safety margin.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125U Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125U |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 125 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 MI40X125U
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 MI40X125U Is Used
Stamping Press Ejection
Uses the 628.3 N push force to knock heavy stamped metal parts out of a die, where the stainless body resists cutting fluid mist.
Package Diverting Arm
Pushes heavy cartons weighing up to 32 kg onto a secondary packing line, relying on the 90-degree U-type rear port for compact hose routing.
Pallet Stopper Gate
Acts as a robust pneumatic stop gate for loaded pallets, absorbing the impact via fixed TPU bumper pads rather than adjustable air cushions.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125U the Right Cylinder?
When sizing this 40 mm bore, stepping down to a Ø32 model drops the 0.5 MPa push force to 402.2 N, while this Ø40 provides 628.3 N; there is no larger standard MI bore available. The U-type back cover orients the rear port at 90 degrees, which helps route hoses cleanly in tight machinery. You can mount it using LB foot brackets, FA flanges, SDB pivot blocks, or TC trunnions.
Remember that a standard double-acting cylinder like this will drift and lose its position if air pressure drops or the valve is centred—the TPU bumpers only soften the end of stroke and act purely as decelerators, never as a locking brake. To suspend a load safely mid-cycle, fit an external rod lock or a pilot-operated check valve. The 125 mm stroke is well within the 500 mm maximum, keeping rod bending stress low for standard loads.
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 MI40X125U 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. The air port size is 1/4 inch.
No, this specific SKU does not include the -S magnet, so it cannot accept CMSG, DMSG or EMSG switches. You would need the -S variant for position sensing. The unit features a stainless-steel riveted round body and fixed TPU bumper pads, not an adjustable air cushion.
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1-Year Warranty
Covers non-human-caused product damage.
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Standard models are processed and dispatched in 3-5 business days.
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Most inquiries answered within 7-8 hours.
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