This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300SCB, 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 SI125X300SCB
The AirTAC SI125 Standard Cylinder SI125X300SCB 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 SAI125X300SCB, 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 → SAI125X300SCB
- 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 SI125X300SCB
The AirTAC SI125X300SCB is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 300 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa, utilizing a G1/2 port and M27x2 rod thread. AirTAC replaced this legacy unit with the SAI125X300SCB, a direct replacement retaining the exact ISO 15552 mounting interface, CB clevis mount, and output force.
The SAI upgrade features a redesigned piston seal with two Y-shaped one-way elements for lower start-up pressure and extended life. Buyers gain new family options like the SAIL lock and BSAI clamp-lock, which the SI lacked. The -S magnet supports legacy CS1-B/DS1-B sensors, while a Viton H seal option raises heat resistance to 150 C.
Airtac SI125 Standard Cylinder SI125X300SCB Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300SCB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300SCB |
| 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 SAI125X300SCB 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 SAI125X300SCB 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 SI125X300SCB
| 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 SI125X300SCB Is Used
Heavy Press Actuation
Drives large forming presses requiring 6136 N push force at 0.5 MPa, utilizing the 300 mm stroke to fully cycle heavy tooling.
Automated Clamp Systems
Secures large fabricated components during machining, relying on the CB clevis mount to absorb pivot stresses safely.
Replacing the Airtac SI125 Standard Cylinder SI125X300SCB with the SAI125X300SCB
To replace the SI125X300SCB, order the SAI125X300SCB. Verify the ISO 15552 interface, 125 mm bore, 300 mm stroke, G1/2 port (PT/G/NPT), CB clevis mounting, and -S magnet. If downsizing, a 100 mm bore yields 3927 N push at 0.5 MPa; if upsizing, a 160 mm bore gives 10053 N. Because the 300 mm stroke invites side-load and rod-bending forces, use external guides to prevent premature wear. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding specify an external pilot check valve, rod lock, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300SCB
- ✓ 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 SI125X300SCB FAQ
Yes, the SI125X300SCB is discontinued. The direct replacement is the SAI125X300SCB. It shares the same ISO 15552 mounting interface, 125 mm bore, 300 mm stroke, G1/2 port, and CB mount, fitting existing fixtures perfectly.
At 0.5 MPa it pushes 6136 N and pulls 5734 N. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical max force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s, and it uses a G1/2 port.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300SCB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300SCB replacement — usually within 7-8 hours.