This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX850, 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 SI125AX850
The AirTAC SI125 Standard Cylinder SI125AX850 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 850mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX850, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke850 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX850
- 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 SI125AX850
The AirTAC SI125AX850 is a discontinued double-acting ISO 15552 profile cylinder with an 850 mm stroke and a SUS420J2 stainless steel piston rod. Delivering 6136 N push force at 0.5 MPa, it is replaced by the SAI125AX850 direct upgrade. This successor shares the exact bore, stroke, G1/2 port and mounting interface, fitting existing fixtures perfectly.
The SAI125AX850 features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. As this SKU lacks a magnet (-S), it cannot accept a CS1-B/DS1-B sensor. For load holding, note the cushion only decelerates; use an external rod lock or pilot check valve.
Airtac SI125 Standard Cylinder SI125AX850 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX850 |
| Bore size | Ø125 mm |
| Stroke | 850 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 SAI125AX850 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 SAI125AX850 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 SI125AX850
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×850 | 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 SI125AX850 Is Used
Heavy Press Staging
Holds and positions large metal panels at the entry of a stamping press using the 6136 N push force, with the SUS420J2 rod resisting coolant corrosion.
Pallet Diverting
Actuates heavy-duty divert arms across a wide 850 mm span to re-route loaded pallets, relying on external guides to absorb side-load stress.
Replacing the Airtac SI125 Standard Cylinder SI125AX850 with the SAI125AX850
To replace the SI125AX850, order the SAI125AX850. Verify the ISO 15552 mounting interface, 125 mm bore, 850 mm stroke, G1/2 port (PT/G/NPT thread options), and your specific mounting accessory. The -A code denotes a SUS420J2 stainless rod for corrosion resistance. Because this is a no-S SKU, it cannot take a magnetic switch. The 850 mm stroke requires external guides to prevent rod bending and side-load damage. A plain cylinder drifts on air loss, so for held loads consider the SAIL or BSAI lock variants, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX850
- ✓ 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 SI125AX850 FAQ
Yes, the SI125AX850 is discontinued. The direct replacement is the SAI125AX850. It shares the same ISO 15552 mounting interface, 125 mm bore, 850 mm stroke, output force, G1/2 port, and SUS420J2 stainless rod, fitting existing fixtures perfectly.
This 125 mm bore cylinder has a G1/2 port. At 0.5 MPa it provides 6136 N push and 5734 N pull force. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX850 replacement — usually within 7-8 hours.