This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X525S, 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 SI125X525S
The AirTAC SI125 Standard Cylinder SI125X525S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 525mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X525S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke525 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X525S
- 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 SI125X525S
The AirTAC SI125X525S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 525 mm stroke. It delivers a thrust of 6136 N at 0.5 MPa, utilizing a G1/2 air port and an M27x2 rod thread. AirTAC replaced this legacy unit with the SAI125X525S, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. It also introduces variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock. This -S model includes a piston magnet for CS1-B/DS1-B sensors, though the SAI family utilizes current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X525S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X525S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X525S |
| Bore size | Ø125 mm |
| Stroke | 525 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 SAI125X525S 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 SAI125X525S 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 SI125X525S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×525 | 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 SI125X525S Is Used
Heavy Press Operations
Drives large forming and stamping presses requiring 6136 N of thrust at 0.5 MPa, utilizing the 125 mm bore for substantial industrial force.
Bulk Material Diversion
Actuates heavy-duty diverter arms on high-capacity conveyor lines, relying on the 30-500 mm/s speed range for controlled movement.
Replacing the Airtac SI125 Standard Cylinder SI125X525S with the SAI125X525S
To replace the SI125X525S, order the SAI125X525S and verify your ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread. Confirm the -S magnet requirement for position sensing. When sizing, neighboring bores offer different forces: the 100 mm bore provides 3927 N push at 0.5 MPa, while the 160 mm bore yields 10053 N. For loads requiring secure holding on air loss, note that a plain cylinder drifts and the 40 mm adjustable air cushion only decelerates near stroke end; consider an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. Because the 525 mm stroke is long, use external guides to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X525S
- ✓ 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 SI125X525S FAQ
Yes, the SI125X525S is discontinued. The direct replacement is the AirTAC SAI125X525S. It shares the same ISO 15552 mounting interface, 125 mm bore, 525 mm stroke, output force, and G1/2 port, fitting directly into existing fixtures.
The 125 mm bore features a G1/2 air port and an M27x2 rod thread. It delivers a push force of 6136 N and a pull force of 5734 N at 0.5 MPa. At 0.7 MPa the push force is 8590 N, and the theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X525S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X525S replacement — usually within 7-8 hours.