Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 125mm stroke, 1/4" air ports and a SUS304 stainless-steel barrel for mildly corrosive environments. For the same bore and stroke it is shorter than an ISO 6432 cylinder, saving mounting space.
- BoreØ40 mm
- Stroke125 mm
- Port size1/4"
- Acting typeDouble acting, adjustable stroke
- Rod threadM14×1.5
- 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 MFJ Adjustable Mini Cylinder MFJ40X125-40
Trimming the extend stroke by up to 40 mm on site, the MFJ40X125-40 lets you dial in the exact end position between 85 and 125 mm without buying a new cylinder. This JIS-standard round-body mini cylinder features a SUS304 stainless barrel and riveted aluminium covers, offering a shorter mounting envelope than an ISO 6432 unit of the same bore.
Driven by a 16 mm rod through a 1/4" port, the 40 mm bore delivers 628.3 N push and 527.8 N pull at 0.5 MPa. That translates to a safe working load of roughly 377 N, or lifting about 32 kg vertically with a 2:1 margin. Fixed TPU bumpers absorb end impacts, and because this SKU lacks the -S magnet, it cannot host CMSG, DMSG or EMSG sensors.
Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 125 mm |
| Acting type | Double acting, adjustable stroke |
| Port size | 1/4" |
| Rod thread | M14×1.5 |
| 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 MF/MFC (JIS-standard) datasheet. Barrel: SUS304 stainless steel; covers: aluminum alloy (round-body, riveted rolling-packed construction). Thread options: PT (blank) / G / NPT.
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 MFJ Adjustable Mini Cylinder MFJ40X125-40
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | Stroke length in mm. |
| -S | Optional built-in magnet for CMSG / DMSG / EMSG sensors. |
MF-family variants: MF / MFC (double acting ±cushion), MSF / MTF (single acting push / pull), MFD / MFCD (double rod ±cushion), MFJ / MFCJ (adjustable stroke ±cushion). Back covers CA / U / CM. Mounting LB / FA / SDB / TC.
Where the Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 Is Used
Changeover Stations
Dial in the 85 to 125 mm extend position during product changeovers, using the 40 mm window to fine-tune the stop without swapping hardware.
Prototype Rigs
Leverage the 628.3 N push force to test actuation distances on new assemblies, adjusting the stroke on the fly as the design evolves.
Variable Position Stops
Set precise end positions for 40 mm bore tooling, relying on the fixed TPU bumpers to absorb impact while the adjuster sets the distance.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 the Right Cylinder?
Choosing between the two bores comes down to force: the MFJ32 pushes 402.2 N at 0.5 MPa, while this MFJ40 steps up to 628.3 N. The 40 mm bore is the right pick when you need that extra thrust to move heavier fixtures. The 40 mm adjustable window is especially useful for trial fits and line changeovers where the exact extend position is not yet finalised.
Mounting options include LB foot, FA flange and TC trunnion (no SDB or back-cover code). Remember that the external adjuster only sets the extend end point—it is not a mid-stroke lock. Because a standard cylinder drifts on air loss, add an external rod lock or pilot check valve if the load must be held.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT / G / NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Back cover (CA/U/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/CM) & mount (LB/FA/SDB/TC).
- check Installation by qualified personnel per AirTAC docs.
Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40 FAQ
This 40 mm bore cylinder has a 1/4" port and a 16 mm rod. 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.
An external adjuster shortens the extend stroke by up to 40 mm, giving a usable range of 85 to 125 mm; retract remains full. This SKU has no magnet, so it cannot take CMSG, DMSG or EMSG switches. Fixed TPU bumpers decelerate the ends.
Authorized Export Seller
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.
Fast Reply
Most inquiries answered within 7-8 hours.
Request a Quote for Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40
Send us the quantity and destination. We confirm price, stock and lead time — usually within 7-8 hours.