Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S
The AirTAC Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S is a genuine double acting, adjustable stroke + cushion standard round-body mini air cylinder with a Ø40mm bore and 70mm stroke, 1/8" air ports and a stainless-steel barrel with a hard-chrome-plated rod for reliable, mildly corrosion-resistant service. A variable air cushion at both ends lets you tune end-of-stroke deceleration on site.
- BoreØ40 mm
- Stroke70 mm
- Port size1/8"
- Acting typeDouble acting, adjustable stroke + cushion
- Rod threadM12×1.25
- CushionVariable air cushion, both ends
- 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 MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S
Twenty millimetres of on-site adjustment is the headline here: within the ordered window, a stop screw shortens the extend stroke of the MACJ40X70-20S to suit the jig in front of you, and a variable cushion at each end tames end-of-stroke shock. Double-acting throughout, it pushes 628.3 N and pulls 527.8 N at 0.5 MPa - figures that climb to 879.6 N and 738.9 N at 0.7 MPa.
Construction is MA-series through and through: a stainless round barrel rolled onto aluminium covers, a 16 mm hard-chrome rod, and a two-way piston seal that stores its own grease, all running 0.15-1.0 MPa (22-145 psi) at 30-800 mm/s. The magnet comes fitted as standard, so a CMSG or EMSG switch bolts on without a special-order piston. In practical terms the 628 N push means about 377 N of usable work at 0.5 MPa - a match for ejecting nylon housings or lifting a 32 kg assembly vertically with headroom to spare.
Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S Technical Specifications
| Model | Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S |
|---|---|
| Series | MACJ mini cylinder |
| Bore size | Ø40 mm |
| Stroke | 70 mm |
| Acting type | Double acting, adjustable stroke + cushion |
| 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 | Variable air cushion, both ends |
| 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 MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S
| MACJ | Standard round-body mini cylinder (adjustable-stroke, variable cushion). |
|---|---|
| 40 | Bore size in mm. |
| ×70 | 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 MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S Is Used
Molded part ejector
Kicking small nylon or ABS housings out of a bench mold: 527.8 N of pull at 0.5 MPa retracts the ejector plate cleanly, and the 20 mm window trims eject height per tool.
Packaging lane diverter
Swinging or pushing cartons between two lanes on a filler line; the dual-end cushion absorbs the divert impact so the frame does not buzz at speed.
Cut-off saw length stop
Setting bar stock length on a small bandsaw: the stop screw sets cut length anywhere in its 20 mm window, with the magnet and an EMSG switch signalling stock-in-place.
Is the Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S the Right Cylinder?
Compare across the MA range before you lock in: at 0.5 MPa a 32 mm bore offers 402.2 N and a 50 mm bore 981.3 N, so the 40 mm is the sensible step when a 32 mm runs out of muscle. The 20 mm window is a mechanical stop for the extend stroke, not a mid-stroke brake - with air off, the piston still moves. Choose FA flange or LB foot mounting, an I or Y rod knuckle where the load pivots, and note the 1/8 inch ports and M12x1.25 rod thread when you draw the fixture.
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 On first run, back off the cushion screws and release gradually.
- check Installation by qualified personnel per AirTAC docs.
Airtac MACJ Stainless Steel Mini Adjustable Cylinder MACJ40X70-20S FAQ
Push is 628.3 N and pull 527.8 N at 0.5 MPa; at 0.7 MPa it is 879.6 N push and 738.9 N pull, with a 128.1 kgf theoretical maximum at 1.0 MPa. The bore is 40 mm, the stroke 70 mm, and the extend stroke can be trimmed by up to 20 mm via the built-in stop screw.
The high-precision stainless barrel and the 16 mm hard-chrome plated rod resist the condensation, cutting fluid and rinse water that pit painted-steel minis. Add the variable cushion at both ends and the standard magnet for CMSG / DMSG / EMSG switches, and the cylinder suits damp or wash-prone stations without extra protection.
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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.
Fast Reply
Most inquiries answered within 7-8 hours.
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