This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X25S, 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 SI125X25S
The AirTAC SI125 Standard Cylinder SI125X25S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 25mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X25S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke25 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X25S
- 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 SI125X25S
The AirTAC SI125X25S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 25 mm stroke. It delivers 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X25S, a direct upgrade retaining the exact ISO 15552 mounting interface, G1/2 port, and M27x2 rod thread.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The SAI family adds SAIL, SAIF, and BSAI lock variants. This -S SKU uses CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X25S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X25S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X25S |
| Bore size | Ø125 mm |
| Stroke | 25 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 SAI125X25S 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 SAI125X25S 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 SI125X25S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×25 | 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 SI125X25S Is Used
Heavy Stamping
Applies 6136 N at 0.5 MPa for short 25 mm stamping and forming actions in automated metal fabrication lines.
Pallet Clamping
Provides robust holding force to secure heavy pallets or fixtures during machining or transfer operations.
Press Ejection
Delivers rapid 30-500 mm/s ejection of finished parts from heavy presses using the 32 mm rod.
Replacing the Airtac SI125 Standard Cylinder SI125X25S with the SAI125X25S
To replace the SI125X25S, order the SAI125X25S. Confirm the ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/2 port, and the -S magnet for CS1-B/DS1-B switches. The 25 mm stroke is very short, so if you need more force, the 160 mm bore offers 10053 N push at 0.5 MPa; if less is needed, the 100 mm bore provides 3927 N. A plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X25S
- ✓ 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 SI125X25S FAQ
Yes, the SI125X25S is discontinued. The direct replacement is the SAI125X25S. It shares the same ISO 15552 mounting interface, 125 mm bore, 25 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
The G1/2 port bore delivers push 6136 N and pull 5734 N at 0.5 MPa, push 8590 N at 0.7 MPa, and a max force of 1251 kgf at 1.0 MPa. The piston rod is 32 mm with an M27x2 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X25S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X25S replacement — usually within 7-8 hours.