Airtac MI25~40 Stainless Steel Mini Cylinder MI40X300SU
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X300SU is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 300mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke300 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 MI40X300SU
Delivering 628.3 N of push force at 0.5 MPa, the AirTAC MI40X300SU is a robust double-acting round-body mini cylinder built for heavy-duty automation. Its stainless-steel barrel and Ø16 rod shrug off mild corrosion and washdown environments better than painted alternatives. The riveted construction keeps the unit compact, while fixed TPU bumper pads absorb stroke-end impacts. A 1/4" port supplies the air, and the U back cover provides a 90-degree mounting orientation.
For practical sizing, plan for a safe working load of about 377 N, which is roughly 60 percent of the 0.5 MPa push rating. This translates to lifting a 32 kg part vertically with a 2:1 safety margin. The built-in magnet (-S) supports CMSG, DMSG, and EMSG position switches, giving you reliable end-of-stroke feedback across the 300 mm travel.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X300SU Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X300SU |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 300 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 MI40X300SU
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 MI40X300SU Is Used
Stamping Press Feed
Pushes heavy metal blanks into a stamping press, utilizing the 628.3 N push force to move 30 kg steel sheets reliably.
Pallet Divertor
Actuates a 90-degree diverting gate on a packaging line, where the U back cover provides the required pivot mounting.
Belt Tensioner
Maintains precise tension on a heavy bulk-material conveyor belt, using the 300 mm stroke to absorb slack.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X300SU the Right Cylinder?
As the largest bore in the MI family, the Ø40 sits at the top of the range with no larger standard size available. If you need less force, stepping down to the Ø32 bore drops the 0.5 MPa push force to 402.2 N. Because this 300 mm stroke is relatively long, carefully manage side loads to prevent rod bending and premature seal wear. The U back cover offers a 90-degree rear pivot, complementing LB foot, FA flange, and TC trunnion options.
Remember that the fixed TPU bumpers only decelerate the piston near the stroke end; they do not act as a brake. If air pressure drops or the valve is centred, the piston will drift and cannot hold a load. To maintain vertical position, integrate an external rod lock or a pilot-operated check valve into your 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 MI40X300SU FAQ
This Ø40 mm bore cylinder features a 1/4" air port and a M12x1.25 male rod thread. At 0.5 MPa it provides 628.3 N push and 527.8 N pull. At 0.7 MPa, push increases to 879.6 N and pull to 738.9 N. The theoretical maximum force is 128.1 kgf at 1.0 MPa.
No, the fixed TPU bumper pads only decelerate the piston at the stroke end and do not function as a locking brake. If air is lost, the piston will drift. For vertical loads, you must use an external rod lock or pilot check valve. The -S magnet allows CMSG/DMSG/EMSG sensors to confirm position.
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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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