Airtac MFJ Adjustable Mini Cylinder MFJ40X25-20
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X25-20 is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 25mm 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
- Stroke25 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 MFJ40X25-20
Trimming the extend stroke by up to 20 mm on site, this JIS-standard round-body mini cylinder saves you from buying a new unit when the exact end position is not yet final. The riveted aluminium covers and SUS304 stainless barrel yield a shorter mounting envelope than an ISO 6432 cylinder for the same 40 mm bore and 25 mm stroke, while resisting mild washdown. A 1/4" port and M14x1.5 male rod thread handle the pneumatic supply.
With a 628.3 N push force at 0.5 MPa, this double-acting actuator targets medium-duty tasks. The external adjuster sets the extend end position within a 5 to 25 mm usable window, but it does not function as a mid-stroke lock. Fixed TPU bumper pads decelerate the stroke ends. This SKU lacks a magnet, so it cannot take a CMSG, DMSG, or EMSG sensor without switching to the -S variant.
Airtac MFJ Adjustable Mini Cylinder MFJ40X25-20 Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X25-20 |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 25 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 MFJ40X25-20
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×25 | 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 MFJ40X25-20 Is Used
Changeover Stations
Dial in the 5 to 25 mm extend position during product changeovers without swapping the cylinder, using the 628.3 N push force to seat medium parts.
Trial Fit Rigs
Use the 20 mm on-site adjuster to find the exact end stop for new tooling, leveraging the compact JIS body to save space in tight fixtures.
Variable Position Stops
Fine-tune the extend end point on the fly for varying material thicknesses, letting the fixed TPU bumpers absorb the 879.6 N peak force at 0.7 MPa.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X25-20 the Right Cylinder?
Choose the MFJ40 over the MFJ32 when you need more push: the 40 mm bore delivers 628.3 N at 0.5 MPa versus 402.2 N for the 32 mm bore. This makes the MFJ40X25-20 suitable for a safe working load around 377 N, or lifting about 32 kg vertically with a 2:1 margin. The 20 mm adjustable window is perfect for trial fits and line changeovers where the final extend position is unknown.
Mounting options include LB foot, FA flange, and TC trunnion (no SDB). Remember that the bumper pads only decelerate the stroke end; they do not hold the load. If air pressure drops, the piston will drift, so fit an external rod lock or pilot check valve for suspended loads.
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 MFJ40X25-20 FAQ
This 40 mm bore cylinder has a 1/4" port and an M14x1.5 male rod thread. It generates 628.3 N push and 527.8 N pull at 0.5 MPa, or 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.
The external adjuster shortens the extend stroke by up to 20 mm, giving a usable extend window of 5 to 25 mm. It sets the end position and is not a mid-stroke lock. Fixed TPU bumper pads decelerate the stroke ends, operating at 30-800 mm/s. This non-S SKU lacks a magnet and cannot accept sensors.
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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.
Fast Reply
Most inquiries answered within 7-8 hours.
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