Airtac MFJ Adjustable Mini Cylinder MFJ40X65-20S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X65-20S is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 65mm 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
- Stroke65 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 MFJ40X65-20S
Trimming the extend end by up to 20 mm on site, the AirTAC MFJ40X65-20S lets you dial in the exact 45 to 65 mm forward position without buying a new unit or adding external stops. This JIS-standard round-body mini cylinder pairs a SUS304 stainless steel barrel with riveted aluminium covers, yielding a body that is physically shorter than an ISO 6432 cylinder of the same bore and stroke to save mounting length.
Driven by filtered air through a 1/4" port, the 40 mm bore delivers 628.3 N of push force at 0.5 MPa. With a built-in magnet enabled by the -S suffix, it supports CMSG, DMSG, and EMSG switches for position sensing. The fixed TPU bumper pads absorb end-of-stroke impact across the 30 to 800 mm/s speed range, and the safe working load sits around 377 N, lifting roughly 32 kg vertically with a 2:1 margin.
Airtac MFJ Adjustable Mini Cylinder MFJ40X65-20S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X65-20S |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 65 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 MFJ40X65-20S
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×65 | 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 MFJ40X65-20S Is Used
Changeover Stations
Fine-tune the 45 to 65 mm extend position during product format changes, using the 20 mm adjuster to set new end stops without swapping hardware.
Trial Fit Rigs
Leverage the 628.3 N push force to seat test components, dialing the stroke back incrementally to find the exact contact depth.
Variable Position Stops
Push 32 kg loads vertically with a 2:1 safety margin, adjusting the extend end on the fly to accommodate different material heights.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X65-20S the Right Cylinder?
When sizing these adjustable cylinders, compare the real thrust: this MFJ40 pushes 628.3 N at 0.5 MPa, whereas the smaller MFJ32 provides 402.2 N. Choose the 40 mm bore when moving heavier jigs or overcoming high friction, and use the external adjuster to shorten the extend stroke by up to 20 mm for trial fits or line changeovers where the final position is not yet final.
Mounting options include LB foot, FA flange, and TC trunnion (no SDB or back-cover code). Because the -S magnet is present, you can fit CMSG, DMSG, or EMSG sensors directly. Remember that the bumper only decelerates the stroke end; the piston drifts on air loss, so install an external rod lock or pilot check valve if you need to hold a suspended load.
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 MFJ40X65-20S FAQ
This 40 mm bore cylinder features a 1/4" air port and an M14x1.5 male rod thread. It delivers 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 maximum 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 45 to 65 mm forward range while retract remains full. The -S suffix means a piston magnet is built in for CMSG, DMSG, or EMSG switches; fixed TPU bumpers decelerate the stroke end.
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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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