This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX950S, 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 SI125AX950S
The AirTAC SI125 Standard Cylinder SI125AX950S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 950mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX950S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke950 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX950S
- 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 SI125AX950S
The AirTAC SI125AX950S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125 mm bore, 950 mm stroke, and a SUS420J2 stainless steel rod. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125AX950S, matching the exact bore, stroke, force, port, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The original -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches. Note that a plain cylinder drifts without live air; use an external rod lock or pilot check valve for load holding.
Airtac SI125 Standard Cylinder SI125AX950S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX950S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX950S |
| Bore size | Ø125 mm |
| Stroke | 950 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 SAI125AX950S 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 SAI125AX950S 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 SI125AX950S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×950 | 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 SI125AX950S Is Used
Heavy Press Actuation
Drives large press fixtures requiring 6136 N push force at 0.5 MPa, utilizing the 950 mm stroke to fully open and close heavy forming dies.
Large Part Diversion
Actuates heavy-duty diverter arms on conveyor lines, relying on the SUS420J2 stainless rod to resist corrosion in humid washdown environments.
Replacing the Airtac SI125 Standard Cylinder SI125AX950S with the SAI125AX950S
To replace the SI125AX950S, order the SAI125AX950S, confirming the ISO 15552 mounting interface, 125 mm bore, 950 mm stroke, G1/2 port, and the -S magnet. The -A rod material specifies SUS420J2 stainless steel for corrosion resistance. If sizing down, a 100 mm bore gives 3927 N push at 0.5 MPa; sizing up to 160 mm yields 10053 N. Because this is a 950 mm stroke, external guides are recommended to prevent rod bending and side-load damage. The air cushion only decelerates the piston at stroke ends and does not hold load on air loss—for secure holding, consider the SAIL or BSAI lock variants, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX950S
- ✓ 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 SI125AX950S FAQ
Yes, the SI125AX950S is discontinued. The direct replacement is the SAI125AX950S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 950 mm stroke, 6136 N force, G1/2 port, and mounting interface.
It features a G1/2 port and M27x2 rod thread. Force ratings are: 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX950S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX950S replacement — usually within 7-8 hours.