Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S
The AirTAC Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S is a genuine double acting, adjustable stroke standard round-body mini air cylinder with a Ø40mm bore and 400mm stroke, 1/8" air ports and a stainless-steel barrel with a hard-chrome-plated rod for reliable, mildly corrosion-resistant service.
- BoreØ40 mm
- Stroke400 mm
- Port size1/8"
- Acting typeDouble acting, adjustable stroke
- Rod threadM12×1.25
- CushionFixed anti-impact 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 MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S
With 628 N of push at 0.5 MPa (and about 880 N at 0.7 MPa), this bore 40 MAJ is the strongest mini in AirTAC's round-body range, built around a 400 mm stroke that can be trimmed by up to 20 mm on site through the external stop screw. It is double acting: air drives the rod both ways, and fixed bumper pads soften each stroke end.
The riveted stainless barrel and hard-chrome plated Dia 16 rod shrug off washdown and damp plant air, an edge painted minis lose quickly. Every unit carries a built-in magnet, so CMSG, DMSG or EMSG switches clip on without special ordering. In practice, budget about 377 N for real work at 0.5 MPa; hung vertically, the rod lifts roughly 32 kg with a 2:1 margin.
Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S Technical Specifications
| Model | Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S |
|---|---|
| Series | MAJ mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 400 mm |
| Acting type | Double acting, adjustable stroke |
| Port size | 1/8" |
| Rod thread | M12×1.25 |
| 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 anti-impact bumper pads |
| Max standard stroke | Up to 500 mm |
Specifications follow the official AirTAC MA-series datasheet. Barrel: stainless-steel tube (round-body, riveted rolling-packed construction); piston rod: carbon steel with 20µm hard-chrome plating; covers: aluminium alloy. Thread options: PT (blank) / G / NPT. Every MA-series cylinder ships with a built-in magnet for CMSG / DMSG / EMSG position sensors.
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 MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S
| MAJ | Standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×400 | Stroke length in mm. |
| -20 | Adjustable stroke window (mm the extend stroke can be shortened on site). |
| -S | Built-in magnet for CMSG / DMSG / EMSG sensors (standard on MA series). |
| CA / U / CM | Back-cover type: CA pivot, U flat-end, CM round-end. |
MA-family variants: MA / MAC (double acting ±cushion), MSA / MTA (single acting push / pull), MAD / MACD (double rod ±cushion), MAJ / MACJ (adjustable stroke ±cushion), MAR (cushioned with integrated F/U mount). Mounting accessories: FA flange, LB foot, SDB pivot; plus I and Y knuckles. Thread PT (blank) / G / NPT.
Where the Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S Is Used
Bottle reject gate
Sweeping mislabeled PET bottles off a filling line conveyor; the 20 mm trim lets maintenance fine-tune where the pusher parks so labels stay clear of the sensor.
Carton flap tucker
Folding the last flap on a case packer - about 377 N of usable force at 0.5 MPa closes RSC flaps without crushing the board.
Press guard slide
Driving a sliding guard door on a small hydraulic press; the magnet feeds door-closed confirmation to a CMSG switch wired into the safety chain.
Is the Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S the Right Cylinder?
Downsizing to a bore 32 MAJ gives 402 N at 0.5 MPa, which suits lighter clamps; nothing in the range out-pushes bore 40, so step up to a larger family if you need more than 628 N. On a 400 mm stroke, keep side loads off the rod and guide the load externally - the slender Dia 16 rod will bend under offset force. Mount via FA flange or LB foot, and add I or Y knuckles if the load pivots. The stop screw is a mechanical end stop only: on air loss the piston still drifts, it is not a mid-stroke lock.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT / G / NPT)
- ✓ Magnet (-S) is standard for sensors
- ✓ Back cover (CA/U/CM) & mount (FA/LB/SDB)
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 Bumper models: keep speed within the rated range.
- check Installation by qualified personnel per AirTAC docs.
Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X400-20S FAQ
At 0.5 MPa it pushes 628.3 N and pulls 527.8 N. Raise supply to 0.7 MPa and those figures become 879.6 N push and 738.9 N pull, with 128.1 kgf as the theoretical maximum at 1.0 MPa. Air supply spans 0.15-1.0 MPa (22-145 psi) and the port is 1/8".
No. Every MAJ ships with the magnet already fitted, so CMSG, DMSG or EMSG switches snap onto the stainless barrel at any point along the 400 mm stroke. Remember sensing tracks position only - the trim screw is an extend end stop, not a load lock.
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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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