This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X252S, 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 SI125X252S
The AirTAC SI125 Standard Cylinder SI125X252S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 252mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X252S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke252 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X252S
- 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 SI125X252S
The AirTAC SI125X252S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 252 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. Because this stroke is non-standard, it was produced as a special order. AirTAC replaced the SI family with the SAI series, making the SAI125X252S the direct upgrade.
The SAI successor retains the same ISO 15552 mounting interface, M27x2 rod thread, and 40 mm cushions, but introduces an upgraded piston seal featuring two Y-shaped one-way elements for lower start-up pressure and longer life. The original SI-S magnet supports legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. For load holding, note that a standard cylinder drifts without live air; consider the SAIL lock or BSAI clamp-lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X252S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X252S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X252S |
| Bore size | Ø125 mm |
| Stroke | 252 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 SAI125X252S 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 SAI125X252S 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 SI125X252S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×252 | 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 SI125X252S Is Used
Heavy-Duty Pressing
Applies 6136 N of thrust at 0.5 MPa for seating bearings, stamping components, or forming light-gauge materials in automated machinery.
Large Clamp Fixtures
Holds substantial welded assemblies or injection molds in place during secondary processing using robust 125 mm bore power.
Replacing the Airtac SI125 Standard Cylinder SI125X252S with the SAI125X252S
To replace the SI125X252S, order the SAI125X252S. Verify your ISO 15552 mounting fixtures (LB, FA, TC, etc.), the G1/2 air port, and the M27x2 rod thread. The -S suffix means a piston magnet is present for position sensing; upgrade from legacy CS1-B/DS1-B switches to current AirTAC equivalents. If you need to adjust force, the neighbouring 100 mm bore yields 3927 N push at 0.5 MPa, while the 160 mm bore provides 10053 N. A standard cylinder does not hold load on air loss; the cushions only decelerate. For secure holding, use an external pilot check valve or specify the SAIL or BSAI lock variant. Since the 252 mm stroke is non-standard and exceeds 200 mm, ensure adequate guide support to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X252S
- ✓ 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 SI125X252S FAQ
Yes, the SI125X252S is discontinued. The direct replacement is the SAI125X252S. It shares the same ISO 15552 mounting interface, 125 mm bore, 252 mm stroke, output force, G1/2 port, and accessories, fitting directly into existing fixtures.
At 0.5 MPa it provides 6136 N push and 5734 pull force. Push force is 8590 N at 0.7 MPa and 11045 N at 0.9 MPa, with a theoretical max of 1251 kgf at 1.0 MPa. It operates at 30-500 mm/s, uses a G1/2 port, and accepts pressures from 0.15 to 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X252S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X252S replacement — usually within 7-8 hours.