This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X240H, with the same bore, stroke, output force, port and mounting, so it fits the same application. The SAI replacement keeps the same ISO 15552 mounting interface, bore, stroke, output force and accessories, so it drops straight into existing fixtures. It is the current-production version of this cylinder with an upgraded piston seal.
Airtac SI125 Standard Cylinder SI125X240H
The AirTAC SI125 Standard Cylinder SI125X240H is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 240mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X240H, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke240 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X240H
- 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 SI125 Standard Cylinder SI125X240H
The AirTAC SI125X240H is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 240 mm stroke. Designed for high-temperature environments, it uses a Viton H seal (0 to 150 C) instead of standard NBR.
Because this SI unit is end-of-life, you should order the direct replacement: SAI125X240H. The SAI maintains the identical ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions, but upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. Note that this specific SKU lacks a magnet (-S) and cannot accept position sensors.
Airtac SI125 Standard Cylinder SI125X240H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X240H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X240H |
| Bore size | Ø125 mm |
| Stroke | 240 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, 40 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI125X240H carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
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 | |
The SAI125X240H produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI125 Standard Cylinder SI125X240H
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×240 | Stroke length in mm. |
| -S | Optional built-in magnet for sensor position sensing. |
Legacy SI-family variants: SID (double rod), SIJ (adjustable stroke) — each maps to its SAI equivalent (SID→SAID, SIJ→SAIJ). Rod material: carbon steel (blank) / SUS420J2 (A) / SUS304 (B).
Where the Airtac SI125 Standard Cylinder SI125X240H Is Used
Hot Stamp Presses
Drives heavy platens in high-temperature stamping cells where the Viton H seal survives ambient heat that degrades standard NBR rubber.
Large Mold Clamping
Secures oversized injection or compression molds using 6136 N of push force at 0.5 MPa, leveraging the rigid ISO 15552 profile barrel.
Heavy Vertical Lifts
Raises 313 kg payloads in vertical material handling setups, relying on the 32 mm piston rod to resist deflection during transit.
Replacing the Airtac SI125 Standard Cylinder SI125X240H with the SAI125X240H
To replace the discontinued SI125X240H, order the SAI125X240H. Verify your ISO 15552 mounting hardware (LB, FA, or TC), the G1/2 air port, and the M27x2 rod thread. Since this is a non-magnetic SKU, it cannot support CS1-B/DS1-B switches; if sensing is needed, select an SAI125X240HS. For sizing, the 125 mm bore yields 6136 N push at 0.5 MPa; if you need less force, consider the 100 mm bore (3927 N), or step up to 160 mm (10053 N) for heavier loads. Operating speed is 30-500 mm/s. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve or the SAIL/BSAI lock variant. With a 240 mm stroke, ensure guide alignment to prevent rod bending under side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X240H
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI125 Standard Cylinder SI125X240H FAQ
Yes, the SI125X240H is discontinued. The direct replacement is the SAI125X240H. It shares the same ISO 15552 mounting interface, 125 mm bore, 240 mm stroke, G1/2 port, and Viton H high-temperature seal, but features an upgraded two Y-shaped element piston seal for longer life.
The 125 mm bore uses a G1/2 air port and features a 32 mm rod with an M27x2 thread. It delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X240H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X240H replacement — usually within 7-8 hours.