This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X330STC, 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 SI125X330STC
The AirTAC SI125 Standard Cylinder SI125X330STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 330mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X330STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke330 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X330STC
- 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 SI125X330STC
The AirTAC SI125X330STC is a discontinued double-acting ISO 15552 profile cylinder with an extruded aluminum barrel, delivering 6136 N push force at 0.5 MPa through its 125 mm bore and 330 mm stroke. It features a G1/2 port, an M27x2 rod thread, and a TC trunnion mount interface.
You must order the direct replacement SAI125X330STC, which shares the exact ISO 15552 mounting dimensions, bore, stroke, and output force. The SAI upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life. The SAI family also adds SAIL and BSAI lock variants the SI lacked.
Airtac SI125 Standard Cylinder SI125X330STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X330STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X330STC |
| Bore size | Ø125 mm |
| Stroke | 330 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 SAI125X330STC 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 SAI125X330STC 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 SI125X330STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×330 | 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 SI125X330STC Is Used
Heavy Press Forming
Drives large metal stamping and forming fixtures requiring high thrust, using the 6136 N push force at 0.5 MPa to deform thick plate materials securely.
Bulk Material Diversion
Actuates heavy-duty diverter arms on aggregate or bulk handling lines, relying on the TC trunnion mount to absorb rotational stress during high-force routing.
Replacing the Airtac SI125 Standard Cylinder SI125X330STC with the SAI125X330STC
To replace the SI125X330STC, order the SAI125X330STC. Confirm the ISO 15552 TC trunnion mount, the G1/2 port (PT/G/NPT thread options), the M27x2 rod, and the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). Sizing both ways: this 125 mm bore yields 6136 N push at 0.5 MPa; if less force is needed, an 80 mm bore gives 2513 N, while a 160 mm bore provides 10053 N. Because the stroke is 330 mm, add external guides to prevent rod bending and side-load wear. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant to hold loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X330STC
- ✓ 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 SI125X330STC FAQ
Yes, the SI125X330STC is discontinued. The direct replacement is the SAI125X330STC. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 330 mm stroke, G1/2 port, TC mount, and force output. The SAI simply upgrades the piston seal to two Y-shaped one-way elements for lower start-up pressure and longer life.
This double-acting cylinder operates at 0.15-1.0 MPa (proof 1.5 MPa) with a speed of 30-500 mm/s. Force output is 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 theoretical max of 1251 kgf at 1.0 MPa. It features a 32 mm rod, M27x2 thread, 40 mm adjustable cushions, and a Viton H seal option for up to 150 C.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X330STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X330STC replacement — usually within 7-8 hours.