Airtac MFJ Adjustable Mini Cylinder MFJ40X250-40
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X250-40 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 MFJ40X250-40
Trimming the extend end by up to 40 mm on-site, the MFJ40X250-40 lets you dial in the exact 210 to 250 mm forward position without buying a new cylinder or adding external stops. As a JIS-standard round-body mini cylinder, its riveted SUS304 stainless steel barrel and aluminium covers form a package that is physically shorter than an ISO 6432 unit of the same bore and stroke, saving valuable mounting length while resisting mild washdown.
Driven by a 16 mm rod through a 1/4" port, this double-acting 40 mm bore generates 628.3 N of push force 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 safety margin. It uses fixed TPU bumper pads to decelerate the stroke end, and because this specific SKU lacks the -S magnet, it cannot accept CMSG, DMSG or EMSG sensors.
Airtac MFJ Adjustable Mini Cylinder MFJ40X250-40 Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X250-40 |
|---|---|
| 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 MFJ40X250-40
| 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 MFJ40X250-40 Is Used
Changeover Stations
Dial in the 210 to 250 mm extend position during product changeovers, using the 40 mm adjuster to set stops for varying part sizes without swapping hardware.
Trial-Fit Rigs
Leverage the 628.3 N push force to seat components in prototype assemblies, fine-tuning the forward stroke on-site until the exact kinematic position is proven.
Variable-Position Stops
Push loads up to 377 N safely in packaging machines, adjusting the extend end by up to 40 mm to accommodate different carton formats on the same line.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X250-40 the Right Cylinder?
When sizing these cylinders, compare the two available bores directly: the MFJ32 delivers 402.2 N of push at 0.5 MPa, whereas this MFJ40 steps up to 628.3 N, making the 40 mm bore the right pick when your trial-fit rig or changeover station needs that extra thrust. The adjustable stroke is ideal for line changeovers where the exact end position is not yet finalised, letting you shorten the extend stroke on the fly.
Mounting options include LB foot, FA flange, and TC trunnion (there is no SDB or back-cover option on this adjustable build). Remember that the external adjuster only sets the end position; it is not a mid-stroke lock. Because a plain cylinder drifts on air loss, you must add an external rod lock or pilot-operated check valve if the load needs to be held safely in place.
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 MFJ40X250-40 FAQ
This 40 mm bore, double-acting cylinder uses a 1/4" port and a 16 mm rod with an M14x1.5 male thread. It delivers 628.3 N push and 527.8 N pull at 0.5 MPa, increasing to 879.6 N push and 738.9 N pull at 0.7 MPa, with a theoretical maximum of 128.1 kgf at 1.0 MPa. The 250 mm base stroke can be shortened by up to 40 mm via the external adjuster.
This specific SKU does not have the -S magnet, so it cannot accept CMSG, DMSG or EMSG switches; you would need the -S variant for sensing. For deceleration, it relies on fixed TPU bumper pads at the stroke end, which absorb impact but do not function as an adjustable air cushion or a load-holding brake.
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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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