Airtac JSI Series Standard Cylinder JSI125X120S
The AirTAC Airtac JSI Series Standard Cylinder JSI125X120S is a genuine double acting JIS-standard air cylinder with a Ø125mm bore and 120mm 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
- Stroke120 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 JSI125X120S
Delivering massive thrust in a compact JIS-standard profile body, the AirTAC JSI125X120S is a double-acting actuator engineered to save valuable machine space. Its extruded, hard-anodized aluminum barrel omits external rods entirely, making the unit noticeably shorter than an equivalent ISO 15552 cylinder of the same 125 mm bore. The heterogeneous two-way piston seal retains grease exceptionally well, ensuring a long, low-friction service life even under demanding cycles.
At 0.5 MPa, this bore generates 6136 N of push force and 5734 N of pull force, peaking at a theoretical 1251 kgf at 1.0 MPa. For real-world sizing, plan for about 3682 N of actual work at 0.5 MPa, which translates to lifting roughly 313 kg vertically with a 2:1 safety margin. The G1/2 port feeds the chamber efficiently, and because this SKU includes the -S magnet, you can drop CMSE or DMSE reed and electronic switches directly into the side sensor grooves for precise position detection.
Airtac JSI Series Standard Cylinder JSI125X120S Technical Specifications
| Model | Airtac JSI Series Standard Cylinder JSI125X120S |
|---|---|
| Series | JSI JIS-standard profile cylinder |
| Bore size | Ø125 mm |
| Stroke | 120 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 JSI125X120S
| JSI | JIS-standard profile cylinder (double-acting type). |
|---|---|
| 125 | Bore size in mm (32 / 40 / 50 / 63 / 80 / 100 / 125). |
| ×120 | 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 JSI125X120S Is Used
Heavy Stamping Press
Generates 8590 N of push at 0.7 MPa to drive heavy stamping dies and form thick steel plates in automotive body-in-white lines.
Pallet Lifter Arm
Lifts loaded pallets of approximately 313 kg vertically with a 2:1 safety margin, taking advantage of the 6136 N available at 0.5 MPa.
Injection Mold Ejector
Pushes large molded plastic parts out of heavy industrial injection molds, relying on the 1251 kgf theoretical maximum force for stubborn releases.
Is the Airtac JSI Series Standard Cylinder JSI125X120S the Right Cylinder?
When sizing this 125 mm bore, stepping down to a 100 mm cylinder drops the 0.5 MPa push force to 3927 N, while the 125 mm is the largest available in the JSI series, meaning there is no larger standard option for even higher loads. The 120 mm stroke operates well within the 1500 mm maximum limit and avoids the side-load and rod-bending concerns that require external guide rails on strokes of 300 mm or more. Remember that the adjustable 33 mm air cushions at both ends only decelerate the piston near the stroke limits; they do not act as a brake. If your application must hold a vertical load when air is lost or the valve is centered, you must add an external rod lock or a pilot-operated check valve to prevent drift.
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 JSI125X120S FAQ
The JSI125X120S features a G1/2 air port and an M27x2.0 rod thread. It delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push and 8028 N pull at 0.7 MPa, with a theoretical maximum force of 1251 kgf at 1.0 MPa.
It is a JIS-standard profile cylinder that is shorter and more compact than an ISO 15552 cylinder of the same 125 mm bore. The extruded hard-anodized aluminum barrel contains no external rods, saving footprint while retaining the option to use CMSE or DMSE sensors via the included -S magnet.
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1-Year Warranty
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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Most inquiries answered within 7-8 hours.
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