Airtac MFJ Adjustable Mini Cylinder MFJ40X300-40S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X300-40S is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 300mm 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
- Stroke300 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 MFJ40X300-40S
Trim the extend end by up to 40 mm right at the machine without buying a new actuator. The AirTAC MFJ40X300-40S is a JIS-standard round-body mini cylinder built with a SUS304 stainless barrel and riveted aluminium covers, giving you a shorter mounting envelope than an ISO 6432 unit for the same 40 mm bore and 300 mm stroke.
This double-acting design pushes with 628.3 N and pulls with 527.8 N at 0.5 MPa, routing air through a 1/4" port. The -S suffix means a piston magnet is fitted for CMSG, DMSG or EMSG switches. Fixed TPU bumpers decelerate the stroke ends, and the 16 mm rod uses an M14x1.5 male thread.
Airtac MFJ Adjustable Mini Cylinder MFJ40X300-40S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X300-40S |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 300 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 MFJ40X300-40S
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 MFJ40X300-40S Is Used
Changeover Stations
Dial in the exact extend position during product changeovers using the 40 mm adjuster, saving setup time on machines handling varied part lengths.
Prototype Test Rigs
Leverage the 628.3 N push force to cycle test components while fine-tuning the end-of-stroke stop on the fly to find the optimal kinematic position.
Variable Position Stops
Use the built-in magnet with DMSG sensors to confirm the shortened extend position, ideal for assembly lines requiring precise but adjustable end stops.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X300-40S the Right Cylinder?
Choose the MFJ40 over the MFJ32 when you need extra muscle: the 40 mm bore delivers 628.3 N of push force at 0.5 MPa, compared to 402.2 N for the 32 mm bore. Both sizes use a 1/4" port, but the larger rod handles higher side loads. The 40 mm adjustable window on this 300 mm base stroke is ideal for trial fits and line changeovers where the exact extend position is not yet final.
Mounting options include LB foot, FA flange and TC trunnion (no SDB or back-cover). Remember that the external adjuster only shortens the extend stroke; it does not lock the load. If you need to hold position against air loss, add an external rod lock or pilot check valve.
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 MFJ40X300-40S FAQ
This 40 mm bore cylinder has a 1/4" air port and a 16 mm rod with an M14x1.5 male thread. At 0.5 MPa it pushes with 628.3 N and pulls with 527.8 N. At 0.7 MPa the push is 879.6 N and pull is 738.9 N. The theoretical maximum force is 128.1 kgf at 1.0 MPa.
The external adjuster lets you shorten the extend stroke by up to 40 mm on site, giving a usable extend range of 260-300 mm, while the retract stroke remains full. The -S suffix indicates a built-in piston magnet for CMSG, DMSG or EMSG switches. Fixed TPU bumpers decelerate the stroke ends.
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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.
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Most inquiries answered within 7-8 hours.
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