Airtac MFJ Adjustable Mini Cylinder MFJ25X40-20S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ25X40-20S is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø25mm bore and 40mm stroke, 1/8" 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.
- BoreØ25 mm
- Stroke40 mm
- Port size1/8"
- Acting typeDouble acting, adjustable stroke
- Rod threadM10×1.25
- 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 MFJ Adjustable Mini Cylinder MFJ25X40-20S
Tune your extend end-position on-site with the AirTAC MFJ25X40-20S, a JIS-standard round-body mini cylinder built with a SUS304 stainless barrel and riveted aluminium covers. An external adjuster lets you shorten the forward stroke by up to 20 mm, giving a usable 20 to 40 mm window without buying a new unit or adding external stops. The riveted construction yields a shorter overall body than an ISO 6432 cylinder for the same 25 mm bore and 40 mm stroke, saving valuable mounting length.
This double-acting actuator delivers 245.3 N of push force at 0.5 MPa and pulls with 206.1 N, operating at 30-800 mm/s on a 1/8" port. The -S suffix equips the piston with a magnet for CMSG, DMSG or EMSG switches. Fixed TPU bumper pads decelerate the stroke ends, while the stainless body resists mild washdown. Based on the 0.5 MPa push rating, it handles a safe working load of about 147 N and lifts roughly 12.5 kg vertically with a 2:1 margin.
Airtac MFJ Adjustable Mini Cylinder MFJ25X40-20S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ25X40-20S |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø25 mm |
| Stroke | 40 mm |
| Acting type | Double acting, adjustable stroke |
| Port size | 1/8" |
| Rod thread | M10×1.25 |
| 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 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 (Ø25mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 245 N | 206 N |
| 0.7 MPa | 344 N | 289 N |
| Max (@1.0 MPa) | 50 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 MFJ25X40-20S
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 25 | Bore size in mm. |
| ×40 | 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 MFJ25X40-20S Is Used
Changeover Stations
Dial in the 20 mm extend window during product changeovers to set new end positions rapidly without swapping hardware.
Trial Fit Rigs
Perfect for prototyping cells where the 245.3 N push force must feed parts to an unverified exact distance before finalizing.
Variable Position Stops
Use the adjuster to shorten the forward stroke on the fly for delicate 12.5 kg vertical lifts requiring precise endpoint control.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ25X40-20S the Right Cylinder?
When sizing these adjustable actuators, compare the real thrust: the MFJ20 provides 157 N of push at 0.5 MPa, this MFJ25 hits 245.3 N, and the larger MFJ32 offers 402.2 N. Choose the 25 mm bore when you need roughly 15 kg of linear force and want on-site adjustability for trial fits or line changeovers where the exact extend position is not yet final.
The external adjuster only sets the forward end stop; it is not a mid-stroke lock, and the cylinder will drift if air pressure drops. For a held load, install an external rod lock or pilot check valve. Mounting options include LB foot, FA flange and TC trunnion (no SDB). Because this is the -S variant, it is fully wired for position sensing.
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 MFJ25X40-20S FAQ
This 25 mm bore cylinder features a 1/8" port and a 10 mm rod with an M10x1.25 male thread. It pushes with 245.3 N and pulls with 206.1 N at 0.5 MPa. At 0.7 MPa, push is 343.4 N and pull is 288.5 N. The theoretical maximum force is 50 kgf at 1.0 MPa.
The external adjuster shortens the extend stroke by up to 20 mm on-site, yielding a 20 to 40 mm usable window; retract remains full. It uses fixed TPU bumper pads for end deceleration, not an adjustable air cushion. The -S suffix means it has a built-in magnet ready for CMSG, DMSG or EMSG sensors.
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.
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