This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X500LB, 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 SI125X500LB
The AirTAC SI125 Standard Cylinder SI125X500LB is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 500mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X500LB, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke500 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X500LB
- 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 SI125X500LB
The AirTAC SI125X500LB is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore, 500 mm stroke, and LB foot mount. Delivering 6136 N push force at 0.5 MPa via a G1/2 port, it is replaced by the SAI125X500LB. This direct successor matches the exact ISO 15552 mounting interface, bore, stroke, force, and port size for existing fixtures.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Since this specific SI SKU lacks the -S magnet suffix, it cannot accept a magnetic sensor.
Airtac SI125 Standard Cylinder SI125X500LB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X500LB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X500LB |
| Bore size | Ø125 mm |
| Stroke | 500 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 SAI125X500LB 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 SAI125X500LB 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 SI125X500LB
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×500 | 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 SI125X500LB Is Used
Heavy Stamping Press
Drives large tooling beds where the 6136 N push force at 0.5 MPa handles substantial die weights and forming resistance.
Pallet Lift Station
Raises loaded pallets vertically, utilizing the 313 kg safe vertical lift capacity while requiring external guides for the 500 mm stroke.
Bulk Material Diversion
Actuates heavy-duty routing gates on high-capacity lines, relying on the LB foot mount to stabilize the long 500 mm extension.
Replacing the Airtac SI125 Standard Cylinder SI125X500LB with the SAI125X500LB
To replace the SI125X500LB, order the SAI125X500LB. Verify the ISO 15552 LB foot mount, 125 mm bore, 500 mm stroke, G1/2 port, and M27x2 rod thread. Because this SKU has no -S magnet, it cannot support position sensing; order a magnet-equipped SAI if switches are needed. If sizing up or down, note the 11045 N push force at 0.9 MPa for the 125 mm bore, or step to a 100 mm bore offering 5497 N. The 500 mm stroke demands external guides to prevent rod bending and side-load damage. Finally, a plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X500LB
- ✓ 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 SI125X500LB FAQ
Yes, the SI125X500LB is discontinued. The direct replacement is the SAI125X500LB. It shares the identical ISO 15552 mounting interface, 125 mm bore, 500 mm stroke, output force, G1/2 port, and LB foot mount, fitting directly into existing machinery.
It uses a G1/2 air port. Force output is 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, with a theoretical maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X500LB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X500LB replacement — usually within 7-8 hours.