This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300S, 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 SI125X300S
The AirTAC SI125 Standard Cylinder SI125X300S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 300mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X300S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke300 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X300S
- 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 SI125X300S
The AirTAC SI125X300S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 300mm stroke. Delivering 6136N push force at 0.5MPa, it is replaced by the SAI125X300S. This direct upgrade matches the exact bore, stroke, G1/2 port, and ISO 15552 mounting interface, fitting existing fixtures perfectly.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family adds SAIL lock and BSAI clamp variants the SI lacked. The -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X300S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300S |
| Bore size | Ø125 mm |
| Stroke | 300 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 SAI125X300S 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 SAI125X300S 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 SI125X300S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×300 | 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 SI125X300S Is Used
Heavy Pressing
Drives large stamping and forming presses requiring 6136N of push force at 0.5MPa with stable 300mm travel.
Pallet Handling
Indexes heavy loaded pallets on transfer lines, utilizing the 313kg vertical lift capacity safely.
Automated Clamping
Secures large fabricated components during machining using the robust 125mm bore profile barrel.
Replacing the Airtac SI125 Standard Cylinder SI125X300S with the SAI125X300S
To replace the SI125X300S, order the SAI125X300S. Confirm the ISO 15552 mounting interface, 125mm bore, 300mm stroke, G1/2 port, and your mounting accessory. The -S magnet enables position sensing. If you need less force, a 100mm bore gives 3927N push at 0.5MPa; for more, a 160mm bore yields 10053N. At 300mm stroke, use an external guide to prevent rod-bending side loads. A plain cylinder drifts on air loss; for load holding, use the SAIL lock, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300S
- ✓ 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 SI125X300S FAQ
Yes, the SI125X300S is discontinued. The direct replacement is the SAI125X300S. It shares the same ISO 15552 mounting interface, 125mm bore, 300mm stroke, output force, and G1/2 port, dropping directly into existing fixtures.
The 125mm bore has a G1/2 port. Forces are: 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa. Speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300S replacement — usually within 7-8 hours.