This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300SN, 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 SI125X300SN
The AirTAC SI125 Standard Cylinder SI125X300SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X300SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X300SN
- 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 SI125X300SN
The AirTAC SI125X300SN is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 300 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features an extruded aluminum barrel, a G1/2 port, M27x2 rod thread, and a -S magnet for CS1-B/DS1-B sensors. The -N NBR seal supports -20 to +70 C. You must order the direct replacement SAI125X300SN, which matches the ISO 15552 mounting interface, output force, and porting.
The SAI upgrade uses an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI variants the SI lacked. Note that standard cylinders drift without live air; use SAIL or an external rod lock for load holding.
Airtac SI125 Standard Cylinder SI125X300SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300SN |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125X300SN 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 SAI125X300SN 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 SI125X300SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125X300SN Is Used
Heavy Pressing
Drives large stamping and forming presses requiring 6136 N push force at 0.5 MPa.
Bulk Diverting
Diverts heavy bulk materials on wide conveyor lines using the 300 mm stroke length.
Replacing the Airtac SI125 Standard Cylinder SI125X300SN with the SAI125X300SN
To replace the SI125X300SN, order the SAI125X300SN. It drops into the exact same ISO 15552 fixtures, matching the 125 mm bore, 300 mm stroke, 6136 N force, and G1/2 port. Confirm your mounting accessory (LB, FA, TC, etc.) and retain the -S magnet for current AirTAC switches. If you need more force than the 6136 N at 0.5 MPa, step up to a 160 mm bore; if less is needed, step down to a 100 mm bore. Because the 300 mm stroke invites rod bending, use an external guide to prevent side loads. For load holding on air loss, select the SAIL lock or BSAI clamp-lock variant, as the standard cushion only decelerates.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300SN
- ✓ 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 SI125X300SN FAQ
Yes, the SI125X300SN is discontinued. The direct replacement is the SAI125X300SN. It is dimensionally interchangeable per the ISO 15552 mounting interface, retaining the same 125 mm bore, 300 mm stroke, force, and G1/2 port.
At 0.5 MPa it pushes 6136 N and pulls 5734 N. At 0.7 MPa it pushes 8590 N, and 11045 N at 0.9 MPa. The theoretical max is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300SN replacement — usually within 7-8 hours.