Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X250-20S
The AirTAC Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X250-20S is a genuine double acting, adjustable stroke standard round-body mini air cylinder with a Ø40mm bore and 250mm stroke, 1/8" air ports and a stainless-steel barrel with a hard-chrome-plated rod for reliable, mildly corrosion-resistant service.
- BoreØ40 mm
- Stroke250 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 MAJ40X250-20S
Position tuning without a machine rebuild is what the -20 option buys on the MAJ40X250-20S: a 250 mm double-acting stroke whose extend end point moves up to 20 mm via an external stop screw. At 0.5 MPa the bore pushes 628.3 N, so the realistic budget for real work is about 377 N, leaving the remainder as reserve for friction and back pressure.
The body is a riveted stack of stainless barrel, aluminium-alloy covers and a stainless block, a build that stays sealed through temperature swings from -20 to +70 C. Force rises to 879.6 N at 0.7 MPa if your supply allows it, and the magnet fitted as standard pairs with EMSG or DMSG switches for end-of-stroke signals.
Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X250-20S Technical Specifications
| Model | Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X250-20S |
|---|---|
| Series | MAJ mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 250 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 MAJ40X250-20S
| MAJ | Standard round-body mini cylinder (adjustable-stroke). |
|---|---|
| 40 | Bore size in mm. |
| ×250 | 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 MAJ40X250-20S Is Used
Case pusher on a palletizing cell
Squares carton rows on a layer plate; 628.3 N at 0.5 MPa moves a full row, and the 20 mm window aligns the push face after the frame is bolted down.
Lowering a fixture onto a weld nest
Drops a clamping bridge over tube assemblies; the stop screw sets the landing height once, and the magnet signals an EMSG switch when seated.
Tensioning a take-up arm on a belt conveyor
Presses a sliding tail pulley outward to stretch the belt; after derating, some 377 N of usable tension remains at 0.5 MPa for a clean, even tracking force.
Is the Airtac MAJ Double Rod Adjustable Stainless Steel Mini Cylinder MAJ40X250-20S the Right Cylinder?
Size down to a 32 mm bore (402.2 N at 0.5 MPa) when the moving mass is small; this 40 mm is the largest MA bore and tops the family at 128.1 kgf theoretical. On a 250 mm stroke, keep side loads low - the 16 mm hard-chrome rod is tough but not a guide bearing, so support the payload on external linear guides. The stop screw is an extend-end stop rather than a holding brake; a loss of air still lets the rod drift. FA flange, LB foot and I or Y knuckles cover the mounting; no SDB code applies to adjustable models.
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 MAJ40X250-20S FAQ
Push is 628.3 N and pull 527.8 N at 0.5 MPa; at 0.7 MPa you get 879.6 N push and 738.9 N pull. Theoretical maximum force is 128.1 kgf at 1.0 MPa. Speed range is 30-800 mm/s and the extend end position is trimmed within the -20 window by the stop screw.
Air ports are 1/8" on this 40 mm bore and the rod thread is M12x1.25 on a 16 mm rod. Mount with an FA flange or LB foot, and add an I or Y rod knuckle if the tooling needs it; adjustable-stroke models have no SDB or back-cover code. Pressure range is 0.15-1.0 MPa (22-145 psi), proof 1.5 MPa (215 psi).
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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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