Airtac MFJ Adjustable Mini Cylinder MFJ40X300-30S
The AirTAC Airtac MFJ Adjustable Mini Cylinder MFJ40X300-30S 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 MFJ40X300-30S
Trim the extend position by up to 30 mm on site with the AirTAC MFJ40X300-30S, a JIS-standard round-body mini cylinder built for double-acting service. The external adjuster lets you dial in the end-of-stroke from 270 to 300 mm without buying a new unit or adding external stops, which is highly useful during trial fits and line changeovers. A 1/4" port and M14x1.5 male rod thread equip the 40 mm bore, while the SUS304 stainless barrel and riveted aluminium covers resist mild washdown.
This size delivers 628.3 N of push force at 0.5 MPa, yielding a safe working load around 377 N or roughly 32 kg of vertical lift with a 2:1 margin. The riveted construction is shorter than an ISO 6432 cylinder for the same stroke, saving valuable mounting length. Because this SKU includes the -S magnet, it is ready for CMSG, DMSG, or EMSG switches.
Airtac MFJ Adjustable Mini Cylinder MFJ40X300-30S Technical Specifications
| Model | Airtac MFJ Adjustable Mini Cylinder MFJ40X300-30S |
|---|---|
| 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 MFJ40X300-30S
| 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 MFJ40X300-30S Is Used
Changeover Stations
Fine-tune the 270 to 300 mm extend end during product format changes without swapping hardware, leveraging the 628.3 N push force to move heavier fixtures.
Trial Fit Rigs
Dial in the exact end position on prototype assemblies where the final stroke length is unknown, using the 30 mm external adjuster to prevent over-travel.
Variable-Position Stops
Act as an adjustable hard stop for 40 mm bore tooling, safely handling a 377 N working load while the SUS304 barrel withstands mild shop splashes.
Is the Airtac MFJ Adjustable Mini Cylinder MFJ40X300-30S the Right Cylinder?
Choose the MFJ40 over the MFJ32 when you need more muscle: the 40 mm bore pushes 628.3 N at 0.5 MPa compared to 402.2 N for the 32 mm bore. The 30 mm adjustable window is perfect for variable-position stops where the exact end point is unknown during commissioning. Mounting options include LB foot, FA flange, and TC trunnion (no SDB or back-cover). Remember that the fixed TPU bumper pads only decelerate the stroke end; they do not lock the load. If you need to hold position 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 MFJ40X300-30S FAQ
This 40 mm bore double-acting cylinder uses a 1/4" port. At 0.5 MPa it pushes 628.3 N and pulls 527.8 N. At 0.7 MPa it pushes 879.6 N and pulls 738.9 N. The theoretical maximum force is 128.1 kgf at 1.0 MPa.
The external adjuster shortens the extend stroke by up to 30 mm on site, giving a usable extend range of 270 to 300 mm; it does not add stroke beyond 300 mm and is not a mid-stroke lock. The -S suffix means a piston magnet is included 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.
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Most inquiries answered within 7-8 hours.
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