This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X540, 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 SI125X540
The AirTAC SI125 Standard Cylinder SI125X540 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 540mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X540, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke540 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X540
- 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 SI125X540
The AirTAC SI125X540 is a discontinued double-acting ISO 15552 profile cylinder delivering 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X540, a direct upgrade retaining the exact 125 mm bore, 540 mm stroke, G1/2 port, and ISO 15552 mounting interface.
The SAI features an upgraded two Y-shaped one-way piston seal for low start-up pressure. This non-magnet SKU cannot take a sensor. The SAI family adds SAIL and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X540 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X540 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X540 |
| Bore size | Ø125 mm |
| Stroke | 540 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 SAI125X540 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 SAI125X540 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 SI125X540
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×540 | 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 SI125X540 Is Used
Heavy Pressing
Drives large stamping or forming presses requiring 6136 N push force at 0.5 MPa.
Pallet Handling
Shifts heavy loaded pallets over a 540 mm stroke in automated distribution centers.
Mold Actuation
Opens and closes substantial industrial molds where a true ISO 15552 fixture fit is required.
Replacing the Airtac SI125 Standard Cylinder SI125X540 with the SAI125X540
To replace the SI125X540, order the SAI125X540 and confirm the ISO 15552 mounting interface, G1/2 port, and M27x2 thread. This non-magnet SKU cannot accept a CS1-B or DS1-B sensor. For sizing, the 125 mm bore yields 6136 N push at 0.5 MPa; dropping to an 80 mm bore gives 2513 N, while a 160 mm bore yields 10053 N. Because the 540 mm stroke is long, use an external guide to prevent rod bending and side-load damage. The air cushion only decelerates; for load holding on air loss, use an external pilot check valve or the SAIL lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X540
- ✓ 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 SI125X540 FAQ
Yes, the SI125X540 is discontinued. The direct replacement is the SAI125X540, which shares the same ISO 15552 mounting interface, 125 mm bore, 540 mm stroke, force, and G1/2 port.
It features a G1/2 port and 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 max force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X540
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X540 replacement — usually within 7-8 hours.