Airtac MFJ Adjustable Mini Cylinder MFJ40X250-20S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X250-20S is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 250mm 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
- Stroke250 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 MFJ40X250-20S
Trimming the extend stroke by up to 20 mm directly at the machine, the AirTAC MFJ40X250-20S lets you set a precise 230 to 250 mm end position without buying a new cylinder. This JIS-standard round-body mini cylinder features a SUS304 stainless barrel and riveted aluminium covers, delivering 628.3 N of push force at 0.5 MPa through its 1/4" port.
The integrated -S piston magnet enables CMSG, DMSG or EMSG switches for end-of-stroke confirmation. For the same bore and stroke, this riveted body is shorter than an ISO 6432 cylinder, saving valuable mounting length while the fixed TPU bumpers absorb impact. It yields a safe working load of roughly 377 N, lifting about 32 kg vertically with a 2:1 margin.
Airtac MFJ Adjustable Mini Cylinder MFJ40X250-20S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X250-20S |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 250 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 MFJ40X250-20S
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×250 | 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 MFJ40X250-20S Is Used
Changeover Stations
Fine-tune the 230 to 250 mm extend endpoint on site to match new product lengths without swapping out the entire actuator.
Trial Fit Rigs
Leverage the 628.3 N push force to seat components and adjust the 20 mm window until the exact clamping position is proven.
Variable Position Stops
Use the external adjuster to shorten the extend stroke for different material thicknesses, avoiding the need for external mechanical stops.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X250-20S the Right Cylinder?
When sizing this adjustable-stroke family, compare both bores: the MFJ32 delivers 402.2 N push at 0.5 MPa, while this MFJ40 provides 628.3 N. Choose the 40 mm bore when moving heavier fixtures, and use the external adjuster to dial in the exact extend endpoint during trial fits or line changeovers. Mounting options include LB foot, FA flange and TC trunnion (no SDB).
Because the -S magnet is present, you can fit CMSG, DMSG or EMSG sensors directly. Remember that the adjuster only sets the end position; it is not a mid-stroke lock. If air pressure drops, the piston drifts, so install an external rod lock or pilot check valve to hold a suspended load safely.
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 MFJ40X250-20S FAQ
This 40 mm bore cylinder has a 1/4" port and a 16 mm rod with an M14x1.5 male thread. It generates 628.3 N push and 527.8 N pull at 0.5 MPa, 879.6 N push and 738.9 N pull at 0.7 MPa, with a theoretical max of 128.1 kgf at 1.0 MPa.
The external adjuster shortens the extend stroke by up to 20 mm on site, giving a usable 230 to 250 mm range. It uses fixed TPU bumper pads to decelerate the stroke end, not an adjustable air cushion. The included -S magnet allows CMSG, DMSG or EMSG sensors to be fitted.
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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