This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X300N, 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 SI125X300N
The AirTAC SI125 Standard Cylinder SI125X300N 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 SAI125X300N, 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 → SAI125X300N
- 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 SI125X300N
The AirTAC SI125X300N is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 300mm stroke. Delivering 6136N push force at 0.5MPa via a G1/2 port, it is replaced by the SAI125X300N. This direct successor shares identical ISO 15552 mounting dimensions, bore, stroke, force, and port specifications for seamless fixture integration.
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, SAIF, and BSAI lock variants absent from the SI line. This NBR-sealed SKU (-N) operates from -20 to +70C and lacks a magnet, meaning it cannot accept CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X300N Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X300N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X300N |
| 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 SAI125X300N 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 SAI125X300N 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 SI125X300N
| 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 SI125X300N Is Used
Heavy Press Forming
Provides the robust 6136N push force at 0.5MPa required for stamping and forming dense metal components in automated fabrication lines.
Pallet Transfer
Handles heavy unit loads and pallets over the 300mm stroke, utilizing the 313kg vertical lift capacity to index goods between conveyors.
Mold Actuation
Drives large molding or clamping fixtures where the G1/2 port and 125mm bore deliver high volume flow for rapid, powerful actuation.
Replacing the Airtac SI125 Standard Cylinder SI125X300N with the SAI125X300N
To replace the SI125X300N, order the SAI125X300N, confirming the ISO 15552 interface, 125mm bore, 300mm stroke, G1/2 port, and NBR seals. Because this 300mm stroke is long, use external guides to prevent rod bending and side-load wear. If sizing up or down, neighboring bores (100mm or 160mm) offer different force classes. A plain cylinder drifts on air loss; the 40mm adjustable cushions only decelerate the piston near stroke end. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants. Note: this no-magnet SKU cannot support position sensing.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X300N
- ✓ 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 SI125X300N FAQ
Yes, the SI125X300N is discontinued. The direct replacement is the SAI125X300N. It is dimensionally interchangeable per ISO 15552, maintaining the same 125mm bore, 300mm stroke, 6136N force, and G1/2 port, so it fits existing mounts directly.
The G1/2 port supplies a 32mm rod. At 0.5MPa it yields 6136N push and 5734N pull. Push force is 8590N at 0.7MPa and 11045N at 0.9MPa, with a theoretical max of 1251kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X300N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X300N replacement — usually within 7-8 hours.