Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X300-20S
The AirTAC Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X300-20S is a genuine double acting, adjustable stroke standard round-body mini air cylinder with a Ø40mm bore and 300mm stroke, 1/8" air ports and a stainless-steel barrel with a hard-chrome-plated rod for reliable, mildly corrosion-resistant service.
- BoreØ40 mm
- Stroke300 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 MAJ40X300-20S
Need a cylinder that adapts to the fixture instead of the other way round? This double-acting 40 mm bore unit turns 628.3 N of push and 527.8 N of pull at 0.5 MPa (879.6 N push at 0.7 MPa) and carries a 20 mm window on its adjustable extend stroke, so one cylinder can be dialed in for several product heights. Supply air sits anywhere in 0.15-1.0 MPa (22-145 psi) with speeds of 30-800 mm/s.
The MA family ships with a built-in magnet on every piston, so CMSG, DMSG or EMSG reed switches clip straight onto the barrel without special orders. Stainless round barrel, hard-chrome 16 mm rod and riveted aluminium-alloy covers give corrosion resistance painted minis cannot match - the difference shows in chill-room condensation or outdoor gate duty. For sizing, count on about 377 N of usable force at 0.5 MPa and roughly 32 kg of vertical lift with a 2:1 margin retained.
Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X300-20S Technical Specifications
| Model | Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X300-20S |
|---|---|
| Series | MAJ mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 300 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 MAJ40X300-20S
| MAJ | Standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×300 | 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 MAJ40X300-20S Is Used
Dairy line cover lifter
Raising stainless guards on a yogurt filling line, the cylinder's 32 kg vertical-lift margin (2:1 on 64 kgf) covers heavy polycarbonate covers while the stainless barrel survives daily caustic rinse.
Injection-mold ejector assist
With extension trimmed up to 20 mm, one cylinder handles multiple mold heights on a small press, pushing 628.3 N at 0.5 MPa - well beyond what the 32 mm bore (402.2 N) could sustain.
Robot gripper home detection
CMSG switches drop onto the standard magnet to confirm gripper retract on a pick-and-place cell, with no special-order piston or bracket machining required.
Is the Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X300-20S the Right Cylinder?
The 32 mm MA bore (402.2 N push / 345.6 N pull at 0.5 MPa) covers lighter ejection work if your force budget stays under 400 N, but anything heavier justifies this 40 mm bore, the biggest in the range. The 20 mm trim window shortens extension only; it is a hard stop at stroke end, so the rod can still creep when supply air is cut and must never be relied on as a brake.
Mount via FA flange or LB foot, add an I or Y knuckle where the load pivots, and keep the 300 mm stroke side-load free by carrying the load in its own external bearings. The 1/8" ports keep plumbing simple on either end.
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 MAJ40X300-20S FAQ
Key figures: 628.3 N push and 527.8 N pull at 0.5 MPa, rising to 879.6 N push and 738.9 N pull at 0.7 MPa, with a theoretical peak of 128.1 kgf at 1.0 MPa. The bore takes 1/8" ports, uses an M12x1.25 male rod thread on a 16 mm rod, runs 30-800 mm/s and works between 0.15-1.0 MPa (22-145 psi), proof tested to 1.5 MPa (215 psi).
No. The external screw is a mechanical end stop that trims the extend stroke within the ordered 20 mm window; beyond the fixed bumper pads it decelerates nothing and does not lock the piston. If air pressure drops, the rod will drift under load, so fit a check or blocking valve wherever position must be held.
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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