Airtac MFJ Adjustable Mini Cylinder MFJ40X20-20S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X20-20S is a genuine double acting, adjustable stroke JIS-standard round-body mini air cylinder with a Ø40mm bore and 20mm 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
- Stroke20 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 MFJ40X20-20S
Fine-tune your extend end position on-site with the AirTAC MFJ40X20-20S, a JIS-standard round-body mini cylinder built with a SUS304 stainless barrel and riveted aluminium covers. An external adjuster lets you shorten the forward stroke by up to 20 mm, ideal for trial fits and line changeovers where the exact travel is not yet final. This 40 mm bore, 20 mm stroke unit delivers 628.3 N of push force at 0.5 MPa.
Because the -S suffix includes a piston magnet, you can mount CMSG, DMSG, or EMSG switches for position sensing. The body is shorter than an ISO 6432 cylinder for the same bore and stroke, saving valuable mounting length. With a safe working load around 377 N, it lifts about 32 kg vertically with a 2:1 margin. The 1/4" port and M14x1.5 male rod thread ensure straightforward integration.
Airtac MFJ Adjustable Mini Cylinder MFJ40X20-20S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X20-20S |
|---|---|
| Series | MFJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 20 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 MFJ40X20-20S
| MFJ | JIS-standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×20 | 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 MFJ40X20-20S Is Used
Changeover Stations
Dial in the exact extend stop during product format changes, using the 20 mm adjuster to shift the end position without swapping cylinders.
Trial Fit Rigs
Safely test end positions on new assemblies with 628.3 N of push force, fine-tuning the travel until the optimal reach is confirmed.
Variable-Position Stops
Set precise physical limits for pushing 32 kg workpieces, relying on the external adjuster rather than adding external hard stops.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X20-20S the Right Cylinder?
When choosing between the two available bores, the MFJ40 offers 628.3 N push at 0.5 MPa, whereas the MFJ32 provides 402.2 N. Select this 40 mm bore if your application needs to lift roughly 32 kg or move heavier fixtures, and drop down to the 32 mm if your load is lighter. The 20 mm adjustable window is perfect for changeover stations requiring variable-position stops.
Mount this cylinder using LB foot, FA flange, or TC trunnion brackets, as SDB and back-cover options are unavailable. Remember that the fixed TPU bumper pads only decelerate the stroke end; they do not lock the load. If you need to hold a vertical load on air loss, install 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 MFJ40X20-20S FAQ
This 40 mm bore cylinder features a 1/4" port and generates 628.3 N push / 527.8 N pull at 0.5 MPa, and 879.6 N push / 738.9 N pull at 0.7 MPa. The theoretical maximum force is 128.1 kgf at 1.0 MPa.
The external adjuster shortens the extend stroke by up to 20 mm on-site; it does not add stroke beyond the 20 mm base or act as a mid-stroke lock. The -S suffix means a piston magnet is built-in for CMSG, DMSG, or EMSG sensors, and 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.
Fast Reply
Most inquiries answered within 7-8 hours.
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