Airtac MI25~40 Stainless Steel Mini Cylinder MI40X400U
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X400U is a genuine double acting round-body mini air cylinder with a Ø40mm bore and 400mm stroke, 1/4" air ports and a stainless-steel barrel and rod for mildly corrosive environments.
- BoreØ40 mm
- Stroke400 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 MI40X400U
Delivering serious muscle for a compact form, this double-acting round-body mini cylinder generates 628.3 N of push force at 0.5 MPa. The stainless-steel barrel and Ø16 mm rod shrug off mild corrosion, making it highly suitable for damp washdown environments where painted steel would degrade. A 1/4" port supplies the air, while fixed TPU bumper pads absorb the impact at each stroke end.
For real-world sizing, plan for a safe working load of roughly 377 N rather than the absolute maximum. This translates to lifting about 32 kg vertically with a 2:1 safety margin, allowing you to match the actuator to actual part weights. The U-style rear cover provides a 90-degree mounting interface, and because this specific SKU lacks the -S magnet, it cannot accept CMSG, DMSG or EMSG position switches.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X400U Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X400U |
|---|---|
| Series | MI mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 400 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 MI40X400U
| MI | round-body mini cylinder (double-acting). |
|---|---|
| 40 | Bore size in mm. |
| ×400 | 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 MI40X400U Is Used
Heavy-Duty Press Ejection
Provides the robust 628.3 N push force required to knock dense stamped metal parts out of a press die, utilizing the 400 mm stroke to clear the work area completely.
Pallet Diverting Arm
Swings a heavy barrier arm via the 90-degree U rear cover to reroute loaded pallets on a packaging line, handling the substantial side-loads encountered during redirection.
Vertical Material Lift Gate
Raises a 30 kg security gate on a washdown wash bay conveyor, leveraging the stainless steel construction to resist moisture while lifting the load within safe limits.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X400U the Right Cylinder?
When sizing this 40 mm bore, compare it directly against its neighbours: a 32 mm bore yields 402.2 N of push at 0.5 MPa, while the 40 mm bore provides 628.3 N. Since 40 mm is the largest available standard MI size, moving beyond this requires a different cylinder family entirely. The 400 mm stroke is well within the 500 mm maximum standard limit, though at this extension you should carefully manage side loading to prevent rod bending.
Remember that a standard double-acting actuator will drift if air pressure drops or the valve is centred, as the TPU pads only decelerate the stroke end rather than locking the load. To suspend a heavy vertical weight safely, fit an external rod lock or a pilot-operated check valve. For high-speed cycles that need precise end-position deceleration, consider the MIC variable air cushion variant instead.
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 MI40X400U FAQ
This 40 mm bore cylinder features a 1/4" air port and a Ø16 mm rod with an M12x1.25 male thread. It generates 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.
No, because this specific SKU lacks the internal magnet. To use CMSG, DMSG or EMSG magnetic switches, you must specify the -S variant. Additionally, this model uses fixed TPU bumper pads to soften stroke-end impacts rather than an adjustable air cushion, and it does not hold its load if air pressure is lost.
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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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