Airtac JSI Series Standard Cylinder JSI125X250S
The AirTAC Airtac JSI Series Standard Cylinder JSI125X250S is a genuine double acting JIS-standard air cylinder with a Ø125mm bore and 250mm 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
- Stroke250 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 JSI125X250S
Delivering massive thrust for heavy-duty automation, this double-acting JIS-standard profile cylinder pushes with 6136 N and pulls with 5734 N at 0.5 MPa. The extruded hard-anodized aluminum barrel omits external rods entirely, making the unit significantly shorter and more compact than an ISO 15552 cylinder of the same 125 mm bore. A heterogeneous two-way piston seal retains grease internally, ensuring low-friction operation over a long service life.
Because the SKU carries the -S suffix, a built-in piston magnet lets CMSE or DMSE switches drop directly into the side grooves for position sensing. 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 unit breathes through a G1/2 port, runs at 30-500 mm/s, and relies on a 33 mm adjustable air cushion at each end to decelerate the 32 mm chrome-plated rod smoothly.
Airtac JSI Series Standard Cylinder JSI125X250S Technical Specifications
| Model | Airtac JSI Series Standard Cylinder JSI125X250S |
|---|---|
| Series | JSI JIS-standard profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 250 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 JSI125X250S
| JSI | JIS-standard profile cylinder (double-acting type). |
|---|---|
| 125 | Bore size in mm (32 / 40 / 50 / 63 / 80 / 100 / 125). |
| ×250 | 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 JSI125X250S Is Used
Stamping Press Feeder
Pushes heavy coil stock or lower dies into a mechanical press, utilizing the 6136 N push force at 0.5 MPa to move substantial mass reliably.
Pallet Dispenser
Indexes empty or loaded wooden pallets at the end of a packaging line, where the 313 kg vertical lift capacity easily handles heavy pallet stacks.
Injection Mold Separation
Parts large molded components from heavy tooling, relying on the 5734 N pull force at 0.5 MPa to break the vacuum and extract the product.
Is the Airtac JSI Series Standard Cylinder JSI125X250S the Right Cylinder?
When sizing this 125 mm bore, the next size down is the 100 mm option, which supplies 3927 N of push force at 0.5 MPa; there is no larger JSI bore available above this class. The integrated -S magnet correctly matches CMSE and DMSE sensors for end-of-stroke confirmation. Remember that a standard pneumatic cylinder drifts if air pressure drops or the valve is centered—the end cushions only slow the piston near stroke limits and do not act as a brake. To suspend a load safely during an emergency stop, fit an external rod lock or a pilot-operated check valve. At a 250 mm stroke, the 32 mm rod is highly robust, but always use external guide rails to absorb any side-loading and prevent rod bending.
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 JSI125X250S FAQ
At 0.5 MPa it provides 6136 N push and 5734 N pull. At 0.7 MPa the output rises to 8590 N push and 8028 N pull, with a theoretical maximum of 1251 kgf at 1.0 MPa. It features a 125 mm bore, a 250 mm stroke, a G1/2 port, an M27x2.0 rod thread, and operates at 30-500 mm/s.
It follows a JIS-standard profile design with an extruded aluminum barrel, making it shorter and more compact than an ISO 15552 cylinder of the same bore. The included -S magnet allows CMSE or DMSE switches to be fitted into the side sensor grooves for precise position detection.
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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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