Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X125-20S
The AirTAC Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X125-20S is a genuine double acting, adjustable stroke standard round-body mini air cylinder with a Ø40mm bore and 125mm stroke, 1/8" air ports and a stainless-steel barrel with a hard-chrome-plated rod for reliable, mildly corrosion-resistant service.
- BoreØ40 mm
- Stroke125 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 MAJ40X125-20S
A workhorse mid-range mover, the MAJ40X125-20S is a double-acting bore 40 mini cylinder whose extend stroke can be shortened up to 20 mm on site with the external stop screw. Rated 628.3 N push and 527.8 N pull at 0.5 MPa, it leaves about 377 N for real work at that pressure - close to lifting 32 kg vertically with a 2:1 margin. The magnet is built in as standard, so CMSG, DMSG or EMSG switches mount without any special piston.
The riveted stainless round body shrugs off splashes and humid shop air that pit painted minis, and the 16 mm hard-chrome rod (M12x1.25 male thread) keeps scoring at bay across 125 mm of travel. Bumper pads are fixed, 1/8" ports feed the air, and the cylinder runs 0.15-1.0 MPa (22-145 psi) at 30-800 mm/s.
Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X125-20S Technical Specifications
| Model | Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X125-20S |
|---|---|
| Series | MAJ mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 125 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 MAJ40X125-20S
| MAJ | Standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×125 | 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 MAJ40X125-20S Is Used
Chute diverter gate
Swing a stainless diverter gate between two filler lanes; 628.3 N of push at 0.5 MPa snaps the gate across in one fast 125 mm move.
Swing clamp on a weld fixture
Close a clamp arm on brackets before a robot welds; 527.8 N of retract force at 0.5 MPa holds the arm seated while the torch passes.
Tray infeed on a thermoformer
Push product trays into a thermoforming chain; the 20 mm trim window lets you match travel to shallow trays without swapping the cylinder.
Is the Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X125-20S the Right Cylinder?
Downsizing to a 32 mm MAJ saves space but drops you to 402.2 N at 0.5 MPa; this 40 mm bore is the largest the MA series makes. The stop screw ends the extend stroke early - it will not hold a load if air is lost, so fit a locking valve when the rod must stay put. Choose FA flange or LB foot mounting, bolt on I or Y knuckles for pivoting loads, and rely on the standard magnet for position switching.
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 MAJ40X125-20S FAQ
At 0.5 MPa it develops 628.3 N on extend and 527.8 N on retract; at 0.7 MPa those figures reach 879.6 N and 738.9 N. The theoretical ceiling at 1.0 MPa is 128.1 kgf. Supply air filtered to 40 um at 0.15-1.0 MPa (22-145 psi).
Every MAJ cylinder leaves the factory with a magnet in the piston, so CMSG, DMSG and EMSG switches snap onto the barrel and read extend or retract position straight away - no magnet-free piston to specify.
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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