Airtac JSI Series Standard Cylinder JSI125X25S
The AirTAC Airtac JSI Series Standard Cylinder JSI125X25S is a genuine double acting JIS-standard air cylinder with a Ø125mm bore and 25mm 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
- Stroke25 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 JSI125X25S
Delivering massive thrust in a tight footprint, the AirTAC JSI125X25S is a JIS-standard double-acting profile cylinder that is physically shorter and more compact than an ISO 15552 unit of the same 125 mm bore. It pushes with 6136 N and pulls with 5734 N at 0.5 MPa, utilizing a hard-anodized aluminum extruded barrel with no external rods to resist wear. The built-in -S piston magnet allows CMSE or DMSE sensors to drop directly into the side grooves for position detection.
For real-world sizing, plan for about 3682 N of actual work at 0.5 MPa, which safely lifts roughly 313 kg vertically with a 2:1 margin. The heterogeneous two-way piston seal retains grease for low-friction life, and the G1/2 port feeds the 32 mm rod to cycle at 30-500 mm/s. Adjustable 33 mm air cushions at both ends absorb impact, while the M27x2.0 rod thread handles heavy loads.
Airtac JSI Series Standard Cylinder JSI125X25S Technical Specifications
| Model | Airtac JSI Series Standard Cylinder JSI125X25S |
|---|---|
| Series | JSI JIS-standard profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 25 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 JSI125X25S
| JSI | JIS-standard profile cylinder (double-acting type). |
|---|---|
| 125 | Bore size in mm (32 / 40 / 50 / 63 / 80 / 100 / 125). |
| ×25 | 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 JSI125X25S Is Used
Press Ejection
Ejects heavy formed metal parts from a 125 mm bore hydraulic press over a quick 25 mm stroke, using the 6136 N push force to break the part free.
Clamping Fixtures
Secures large steel castings in a machining center, applying 5734 N of pull at 0.5 MPa to lock the block against the stops for milling.
Pallet Stoppers
Halts loaded 500 kg pallets on a heavy-duty conveyor, absorbing the kinetic energy via the 33 mm adjustable air cushions before signaling the next station.
Is the Airtac JSI Series Standard Cylinder JSI125X25S the Right Cylinder?
If 6136 N of push at 0.5 MPa is too much, the next size down is the 100 mm bore offering 3927 N; since 125 mm is the largest JSI available, moving higher requires a different series. This 25 mm stroke moves a heavy load over a short distance, but if air pressure drops or the valve centers, the piston will drift because the cushion only decelerates near the end of travel—install a pilot-operated check valve or external rod lock to hold the load safely. The included -S magnet pairs perfectly with CMSE/DMSE switches.
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 JSI125X25S FAQ
At 0.5 MPa it pushes with 6136 N and pulls with 5734 N. At 0.7 MPa the push is 8590 N and pull is 8028 N, with a theoretical maximum of 1251 kgf at 1.0 MPa. The air port is G1/2, the rod is 32 mm with an M27x2.0 thread, and speed ranges from 30-500 mm/s.
The JSI125X25S is a JIS-standard profile cylinder that is shorter and more compact than an ISO 15552 cylinder of the same 125 mm bore, saving valuable machine space. It uses a hard-anodized aluminum extruded barrel instead of external rods, and the -S suffix means it has a built-in magnet for CMSE/DMSE sensors.
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Covers non-human-caused product damage.
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Standard models are processed and dispatched in 3-5 business days.
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