Airtac MFCJ Adjustable Mini Cylinder MFCJ40X125-20S
The AirTAC Airtac MFCJ Adjustable Mini Cylinder MFCJ40X125-20S is a genuine double acting, adjustable stroke + cushion 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 + cushion
- Rod threadM14×1.5
- CushionVariable air cushion, both ends
- 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 MFCJ Adjustable Mini Cylinder MFCJ40X125-20S
Tune both travel and end-of-stroke shock precisely with this 40 mm bore, 125 mm stroke adjustable mini cylinder. A built-in magnet (-S) enables CMSG, DMSG, or EMSG switches, while the external adjuster lets you shorten the extend stroke by up to 20 mm on-site (usable extend 105-125 mm). The SUS304 stainless steel barrel and riveted aluminium covers form a JIS-standard round body that is shorter than an ISO 6432 cylinder for the same stroke, saving valuable mounting length.
Delivering 628.3 N push and 527.8 N pull at 0.5 MPa, this double-acting actuator handles robust workloads. The variable air cushion at both ends soaks up high-speed kinetic energy for smooth stops. It provides a safe working load of about 377 N (roughly 60% of the 0.5 MPa push force) and lifts about 32 kg vertically with a 2:1 margin. Air connects via a 1/4" port.
Airtac MFCJ Adjustable Mini Cylinder MFCJ40X125-20S Technical Specifications
| Model | Airtac MFCJ Adjustable Mini Cylinder MFCJ40X125-20S |
|---|---|
| Series | MFCJ JIS mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 125 mm |
| Acting type | Double acting, adjustable stroke + cushion |
| 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 | Variable air cushion, both ends |
| 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 MFCJ Adjustable Mini Cylinder MFCJ40X125-20S
| MFCJ | JIS-standard round-body mini cylinder (adjustable-stroke, variable cushion). |
|---|---|
| 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 MFCJ Adjustable Mini Cylinder MFCJ40X125-20S Is Used
High-Speed Forming Press
Dial in the 105-125 mm extend stroke on the fly and rely on the variable air cushion to absorb the 879.6 N push force shock at 0.7 MPa during rapid metal forming.
Package Divert Arm
Adjust the 20 mm stroke window to match varying box sizes precisely while using the 628.3 N push force to redirect heavy goods on a high-speed sorting line.
Pallet Stopper Gate
Tune the stopping position and cushion needle to halt pallets smoothly; the SUS304 stainless barrel resists washdown moisture in damp logistics environments.
Is the Airtac MFCJ Adjustable Mini Cylinder MFCJ40X125-20S the Right Cylinder?
Choose the MFCJ40 over the MFCJ32 when you need extra force: the 40 mm bore yields 628.3 N push at 0.5 MPa compared to 402.2 N for the 32 mm bore. This larger bore is optimal for high-speed changeovers where the exact extend position (adjustable within the 20 mm window) and end-of-stroke shock both require field tuning. The needle air cushion decelerates the piston near stroke end but does not lock the load; if air pressure drops, the piston drifts. For vertical or suspended loads that must hold position on air loss, add an external rod lock or pilot-operated check valve.
Mount this JIS-standard cylinder using LB foot, FA flange, or TC trunnion brackets (no SDB or back-cover mount is available on this adjustable build). The -S magnet in this SKU supports CMSG, DMSG, and EMSG reed or electronic sensors for position confirmation.
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 MFCJ Adjustable Mini Cylinder MFCJ40X125-20S FAQ
This 40 mm bore cylinder has a 1/4" air port and a male M14x1.5 rod thread. It generates 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 force of 128.1 kgf at 1.0 MPa.
The external adjuster shortens the extend stroke by up to 20 mm (usable range 105-125 mm), while the retract stroke remains full. The variable air cushion at both ends uses a needle valve to decelerate the piston near the ends for smooth, quiet operation. The -S magnet allows CMSG, DMSG, and EMSG sensors to track position.
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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