This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X725S, 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 SI125X725S
The AirTAC SI125 Standard Cylinder SI125X725S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 725mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X725S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke725 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X725S
- 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 SI125X725S
The AirTAC SI125X725S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 725 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features a G1/2 port, M27x2 rod thread, and a 40 mm adjustable air cushion. AirTAC replaced this legacy unit with the SAI125X725S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. The SAI family also adds SAIL and BSAI lock variants the SI lacked. This -S SKU uses CS1-B/DS1-B sensors, while Viton H seals raise heat resistance to 150 C.
Airtac SI125 Standard Cylinder SI125X725S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X725S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X725S |
| Bore size | Ø125 mm |
| Stroke | 725 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 SAI125X725S 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 SAI125X725S 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 SI125X725S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×725 | 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 SI125X725S Is Used
Heavy Press Stands
Applies 6136 N at 0.5 MPa to seat large bearings or form heavy gauge metal components securely.
Pallet Diverters
Extends 725 mm to push loaded pallets across transfer lines, requiring external guides to manage side loads.
Replacing the Airtac SI125 Standard Cylinder SI125X725S with the SAI125X725S
To replace the SI125X725S, order the SAI125X725S. Confirm the ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/2 port, and the -S magnet for current AirTAC switches. Sizing both ways: a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. If you need to hold the load without live air, the cushion only decelerates; use an external pilot check valve or the SAIL/BSAI lock variant. For the 725 mm stroke, use external guides to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X725S
- ✓ 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 SI125X725S FAQ
Yes, the SI125X725S is discontinued. The direct replacement is the SAI125X725S. It shares the identical ISO 15552 mounting interface, 125 mm bore, 725 mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
It uses a G1/2 port. 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. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X725S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X725S replacement — usually within 7-8 hours.