This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125AX650S, 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 SI125AX650S
The AirTAC SI125 Standard Cylinder SI125AX650S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 650mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125AX650S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke650 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125AX650S
- 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 SI125AX650S
The AirTAC SI125AX650S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 650 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125AX650S, sharing the same ISO 15552 mounting interface, stroke, force, and accessories.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The -A suffix denotes a SUS420J2 stainless steel rod, and -S means a magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125AX650S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125AX650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125AX650S |
| Bore size | Ø125 mm |
| Stroke | 650 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 SAI125AX650S 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 SAI125AX650S 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 SI125AX650S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×650 | 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 SI125AX650S Is Used
Heavy Press Forming
Applies the 8590 N push at 0.7 MPa for forming heavy-gauge components, utilizing the adjustable 40 mm cushion to absorb end-of-stroke impact.
Replacing the Airtac SI125 Standard Cylinder SI125AX650S with the SAI125AX650S
To replace this SI125AX650S, order the SAI125AX650S. Confirm the ISO 15552 mounting interface, 650 mm stroke, G1/2 port, and SUS420J2 rod. The 125 mm bore yields 6136 N push at 0.5 MPa; sizing down to 100 mm gives 3927 N. This cylinder does not hold load without live air; use an external rod lock or pilot check valve, or the SAIL/BSAI lock variant. At 650 mm, prevent rod bending by using external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125AX650S
- ✓ 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 SI125AX650S FAQ
Yes, the SI125AX650S is discontinued. The direct replacement is the SAI125AX650S. It is dimensionally interchangeable per ISO 15552, keeping the same 125 mm bore, 650 mm stroke, G1/2 port, and mounting interface.
It features a G1/2 port. The 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125AX650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125AX650S replacement — usually within 7-8 hours.