Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40S 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 MFJ40X125-40S
Trimming the extend end by up to 40 mm on-site, this double-acting JIS-standard round-body mini cylinder saves you from buying new parts when the exact 85 to 125 mm end position is not yet final. The SUS304 stainless barrel and riveted aluminium covers form a compact body that is physically shorter than a comparable ISO 6432 unit, yielding a practical safe working load of roughly 377 N. Because the -S suffix equips the piston with a magnet, you can mount CMSG, DMSG or EMSG switches directly for position sensing.
Driven by a 16 mm rod through a 1/4" port, the 40 mm bore delivers 628.3 N of push force at 0.5 MPa. The fixed TPU bumper pads absorb end-of-stroke impact across the 30 to 800 mm/s speed range, and the external adjuster functions purely as a stroke limiter, not a mid-travel lock.
Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40S |
|---|---|
| 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 MFJ40X125-40S
| 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 MFJ40X125-40S Is Used
Changeover Dial-In
Fine-tune the extend position within the 40 mm window during format changeovers, avoiding the need to swap cylinders for different product sizes.
Prototype Stroke Setup
Perfect for trial rigs where the final extend length is unknown, letting you safely test positions with 628.3 N of push force before locking the adjuster.
Variable Position Stops
Acts as an adaptable hard stop for assembly stations, providing repeatable end positions while the built-in magnet confirms stroke completion.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X125-40S the Right Cylinder?
When sizing these adjustable units, compare both bores directly: this MFJ40 pushes 628.3 N at 0.5 MPa, while the smaller MFJ32 delivers 402.2 N. Choose the 40 mm bore when your trial fits or line changeovers involve heavier moving masses, using the 40 mm adjuster window to dial in the exact extend stop without external hardware. For mounting, select LB foot, FA flange or TC trunnion brackets (SDB is unavailable). Remember that air pressure alone does not hold the load if supply drops, the piston drifts, so fit an external rod lock or pilot check valve for vertical safety.
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 MFJ40X125-40S FAQ
This 40 mm bore cylinder uses a 1/4" port and a 16 mm rod. It generates 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 external adjuster shortens the extend stroke by up to 40 mm on-site, giving a usable 85 to 125 mm window. End-of-stroke deceleration is handled by fixed TPU bumper pads, not an adjustable air cushion. The -S suffix provides a magnet 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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