Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125SR
The AirTAC Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125SR 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 MI40X125SR
Delivering 628.3 N of push force at 0.5 MPa, this double-acting round-body mini cylinder handles heavy-duty automation tasks. The Ø40 bore operates with a 1/4" port and a Ø16 piston rod featuring an M12x1.25 male thread. Its stainless-steel barrel and rod resist mild corrosion, making it highly suitable for damp washdown environments where painted steel alternatives would degrade. The riveted construction keeps the body compact, while fixed TPU bumper pads absorb impact energy at the stroke extremes.
Because it lacks adjustable air cushioning, you should plan for a safe working load of roughly 377 N (about 60 percent of the 0.5 MPa rating) to ensure reliable operation. This translates to lifting around 32 kg vertically when applying a 2:1 safety margin. The built-in piston magnet (-S) supports CMSG, DMSG, and EMSG position switches, and the R back cover provides an axial-in port orientation to simplify plumbing in tight machinery layouts.
Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125SR Technical Specifications
| Model | Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125SR |
|---|---|
| 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 MI40X125SR
| 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 MI40X125SR Is Used
Stamping Press Feeders
Pushes heavy metal blanks into a stamping press using the 628.3 N extend force, with the 125 mm stroke moving parts cleanly into the die area.
Pallet Diverters
Actuates heavy routing gates on a packaging conveyor, relying on the stainless steel construction to endure humid washdown cleaning cycles.
Vertical Package Lifts
Raises 30 kg cartons between tiered conveyor elevators, safely operating within the computed 32 kg vertical lift capacity at a 2:1 margin.
Is the Airtac MI25~40 Stainless Steel Mini Cylinder MI40X125SR the Right Cylinder?
When sizing this 125 mm stroke actuator, compare it against the adjacent bores: the Ø32 generates 402.2 N of push at 0.5 MPa, whereas this Ø40 provides 628.3 N. There is no larger standard MI bore, so for loads exceeding this capacity, you must switch to a different cylinder family entirely. The 125 mm stroke is well within the 500 mm maximum standard limit, keeping the unit readily available without made-to-order delays.
Remember that a standard double-acting cylinder will drift if air pressure drops or the control valve is centred; the TPU bumpers only soften the end-of-stroke impact and cannot act as a braking mechanism. To suspend a load safely during an emergency stop or air loss, fit an external pilot-operated check valve or a dedicated rod lock. The -S magnet allows seamless integration with CMSG, DMSG, or EMSG sensors for end-position confirmation.
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 MI40X125SR FAQ
This double-acting cylinder uses a 1/4" air port and generates 628.3 N push and 527.8 N pull at 0.5 MPa. At 0.7 MPa, the push increases to 879.6 N and the 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 near the stroke ends; they are not an adjustable air cushion and cannot lock the rod. If air is lost, the piston will drift, so you must add an external rod lock or pilot check valve to hold a vertical load. The -S magnet allows CMSG, DMSG, and EMSG sensors for position detection.
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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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