Airtac JSI Series Standard Cylinder JSI125X280S
The AirTAC Airtac JSI Series Standard Cylinder JSI125X280S is a genuine double acting JIS-standard air cylinder with a Ø125mm bore and 280mm stroke, G1/2 air ports and adjustable end cushioning. Its no-tie-rod, hard-anodized profile barrel is more compact than an ISO 15552 cylinder of the same bore — a space-saver on tight machines.
- BoreØ125 mm
- Stroke280 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- CushionAdjustable, 33 mm
- 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 JSI Series Standard Cylinder JSI125X280S
Generating 6136 N of push force at 0.5 MPa, this double-acting JIS-standard profile cylinder is built for heavy-duty automation. The extruded hard-anodized aluminum barrel omits external rods, making the unit noticeably shorter and more compact than an ISO 15552 cylinder of the same 125 mm bore. A heterogeneous two-way piston seal retains grease for long, low-friction life, while the -S suffix indicates a built-in piston magnet for position sensing.
Because 6136 N is a theoretical maximum, plan for about 3682 N of real work at 0.5 MPa, which translates to lifting roughly 313 kg vertically with a 2:1 safety margin. The G1/2 air port handles the 30-500 mm/s operating speed range, and the integrated magnet allows CMSE or DMSE switches to drop directly into the side sensor grooves.
Airtac JSI Series Standard Cylinder JSI125X280S Technical Specifications
| Model | Airtac JSI Series Standard Cylinder JSI125X280S |
|---|---|
| Series | JSI JIS-standard profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 280 mm |
| Acting type | Double acting |
| Port size | G1/2 |
| Rod thread | M27×2.0 |
| 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 – 500 mm/s |
| Cushion | Adjustable, 33 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC JSI (JIS standard) datasheet. Confirm against the product label before installation. Thread options: PT (blank) / G. Barrel: hard-anodized aluminum profile (no tie rods).
Theoretical Output Force (Ø125mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 6136 N | 5734 N |
| 0.7 MPa | 8590 N | — |
| Max (@1.0 MPa) | 1251 kgf | |
Actual usable force is lower than theoretical due to friction and back-pressure. Size with a safety margin.
Model Code: Airtac JSI Series Standard Cylinder JSI125X280S
| JSI | JIS-standard profile cylinder (double-acting type). |
|---|---|
| 125 | Bore size in mm (32 / 40 / 50 / 63 / 80 / 100 / 125). |
| ×280 | Stroke length in mm. |
| -S | Optional built-in magnet for CMSE / DMSE sensors. |
JSI-family variants: JSI (double acting), JSID (double rod), JSIJ (adjustable stroke). Mounting: LB / FA / FB / CA / CB / CR / TC / TCM1 / TCM2. Thread PT (blank) / G.
Where the Airtac JSI Series Standard Cylinder JSI125X280S Is Used
Heavy Press Ejection
Provides the robust push force needed to eject thick steel blanks from a mechanical press, using the 280 mm stroke to clear the die bed completely.
Pallet Dispenser Pusher
Separates empty pallets from a magazine stack, leveraging the 313 kg vertical lift equivalent to slide heavy wooden pallets onto an inbound conveyor chain.
Injection Mold Platen Shift
Shifts a large injection molding platen into the unload position, relying on the compact JIS profile to fit within tight machine guarding.
Is the Airtac JSI Series Standard Cylinder JSI125X280S the Right Cylinder?
At the top of the JSI range, there is no larger standard bore, so if 6136 N at 0.5 MPa is insufficient, you must move to a different cylinder family. Stepping down to the 100 mm bore drops the push force to 3927 N, making this 125 mm model the correct choice when you need roughly 3682 N of safe working load. The 280 mm stroke falls well under the 1500 mm maximum, keeping the assembly rigid without excessive rod overhang.
Note that a standard pneumatic cylinder does not hold its load if air pressure is lost or the valve is centered; the piston will drift, as the adjustable 33 mm air cushions only decelerate the stroke near the end points. For suspended or vertical loads, install an external rod lock or a pilot-operated check valve. The -S magnet on this SKU enables CMSE/DMSE sensors for end-of-stroke confirmation.
Quick checklist
- ✓ Required force at your working pressure
- ✓ Stroke and mounting space
- ✓ Port/thread type (PT / G / NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Side load — consider a guided cylinder
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 Set cushions to minimum, then release gradually.
- check Use correct mounting accessory (LB/FA/FB/CA/CB/TC).
- check Installation by qualified personnel per AirTAC docs.
Airtac JSI Series Standard Cylinder JSI125X280S FAQ
This 125 mm bore cylinder features a G1/2 port and an M27x2.0 rod thread. The thrust output is 6136 N push and 5734 N pull at 0.5 MPa, increasing to 8590 N push and 8028 N pull at 0.7 MPa. The theoretical maximum force at 1.0 MPa is 1251 kgf.
The JSI is a JIS-standard profile cylinder that is shorter and more compact than an ISO 15552 cylinder of the same bore. It uses an extruded hard-anodized aluminum barrel without external rods to save machine space while retaining heavy-duty performance.
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Standard models are processed and dispatched in 3-5 business days.
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