This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X800STC, 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 SI125X800STC
The AirTAC SI125 Standard Cylinder SI125X800STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 800mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X800STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke800 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X800STC
- 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 SI125X800STC
The AirTAC SI125X800STC is a discontinued double-acting ISO 15552 profile cylinder with an 800 mm stroke and TC trunnion mount. Built for heavy loads, it delivers 6136 N push force at 0.5 MPa through a G1/2 port. AirTAC replaced this legacy unit with the SAI125X800STC, a direct upgrade sharing the exact same ISO 15552 mounting interface, bore, and stroke.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original SI-S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family introduces lock variants like SAIL and BSAI absent in the SI line.
Airtac SI125 Standard Cylinder SI125X800STC Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X800STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X800STC |
| Bore size | Ø125 mm |
| Stroke | 800 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 SAI125X800STC 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 SAI125X800STC 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 SI125X800STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×800 | 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 SI125X800STC Is Used
Heavy Press Ejection
Delivers 6136 N at 0.5 MPa to eject dense stamped parts from heavy presses, utilizing the 800 mm stroke to clear the die area completely.
Pallet Discharge
Ideal for pushing loaded pallets along roller conveyors, where the TC trunnion mount absorbs moment loads during the long 800 mm transfer.
Large Mold Handling
Shifts heavy industrial molds into machining centers, taking advantage of the 125 mm bore's substantial thrust and extended travel distance.
Replacing the Airtac SI125 Standard Cylinder SI125X800STC with the SAI125X800STC
To replace the SI125X800STC, order the SAI125X800STC. Verify your ISO 15552 TC trunnion mounting, 125 mm bore, 800 mm stroke, and G1/2 port (PT/G/NPT). The -S magnet works with legacy CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors. If you need more force, step up to a 160 mm bore; if less, drop to 100 mm. Note that a plain cylinder drifts without live air—the cushion only decelerates—so use a pilot check valve or SAIL/BSAI lock for holding. At 800 mm, prevent rod bending by using an external guide to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X800STC
- ✓ 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 SI125X800STC FAQ
Yes, the SI125X800STC is discontinued. The direct replacement is the SAI125X800STC. It shares the identical ISO 15552 mounting interface, 125 mm bore, 800 mm stroke, force, and G1/2 port, fitting existing fixtures perfectly.
At 0.5 MPa it pushes 6136 N and pulls 5734 N. Push force is 8590 N at 0.7 MPa and 11045 N at 0.9 MPa, with a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X800STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X800STC replacement — usually within 7-8 hours.