Airtac MI25~40 Stainless Steel Mini Cylinder MI40X55U
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X55U is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 55mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke55 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 MI40X55U
Delivering 628.3 N of push force at 0.5 MPa, this double-acting round-body mini cylinder handles heavy-duty automation tasks. The stainless-steel barrel and rod shrug off mild corrosion, making it superior to painted alternatives in damp environments. It features a 1/4" air port and a U-type back cover that orients the rear port at 90 degrees for tight machinery layouts.
Instead of adjustable cushioning, fixed TPU bumper pads absorb the impact at stroke extremes. Because this SKU lacks the -S magnet, it cannot accept CMSG, DMSG or EMSG position switches. Plan for roughly 377 N of actual work at 0.5 MPa, which means it lifts about 32 kg vertically with a 2:1 safety margin.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X55U Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X55U |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 55 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 MI40X55U
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×55 | 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 MI40X55U Is Used
Stamping Press Ejection
Pushes heavy metal blanks out of a stamping die using 628.3 N of force, with the 90-degree U-cover port keeping air lines clear of the press ram.
Pallet Diverting Gate
Actuates a heavy mechanical gate to redirect loaded pallets, safely handling the 32 kg vertical lift equivalent without bending the 16 mm rod.
Carton Flap Folding
Folds thick cardboard flaps on automated packaging lines, relying on the stainless-steel body to withstand washdowns during shift changes.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X55U the Right Cylinder?
Sizing this 40 mm bore against its neighbours shows its place in the lineup: a 32 mm bore provides 402.2 N push at 0.5 MPa, while the 40 mm bore jumps to 628.3 N. As the largest standard AirTAC mini cylinder size, there is no larger bore available in this series. The 55 mm stroke is well within the 500 mm maximum standard stroke, keeping the rod highly resistant to bending under compression.
Note that this plain cylinder will drift and drop its load if air pressure is lost or the valve is centred; the TPU bumpers only decelerate the stroke end and act as neither a brake nor a lock. For suspended loads, install an external rod lock or a pilot-operated check valve. The U-type rear cover provides a 90-degree porting angle to simplify hose routing.
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 MI40X55U FAQ
At 0.5 MPa it pushes 628.3 N and pulls 527.8 N. At 0.7 MPa it pushes 879.6 N and pulls 738.9 N. The theoretical maximum force is 128.1 kgf at 1.0 MPa. The air port is 1/4" and the male rod thread is M12x1.25.
No, this specific SKU does not include a magnet. You must select an -S variant to use CMSG, DMSG or EMSG switches. Additionally, the fixed TPU bumper pads only decelerate the stroke end; they do not function as an adjustable air cushion.
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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.
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Most inquiries answered within 7-8 hours.
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