This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X325, 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 SI125X325
The AirTAC SI125 Standard Cylinder SI125X325 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 325mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X325, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke325 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X325
- 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 SI125X325
The AirTAC SI125X325 is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 325mm stroke. It delivers 6136N push force at 0.5MPa via a G1/2 port. AirTAC replaced this unit with the SAI125X325, a direct upgrade retaining the exact mounting interface, stroke, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X325 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X325 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X325 |
| Bore size | Ø125 mm |
| Stroke | 325 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 SAI125X325 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 SAI125X325 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 SI125X325
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×325 | 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 SI125X325 Is Used
Heavy Press Operations
Ideal for high-tonnage pressing and forming tasks requiring a robust 6136N push force at 0.5MPa over a 325mm travel distance.
Large Mold Handling
Actuates heavy industrial molds and platens, utilizing the 125mm bore and adjustable 40mm cushions to decelerate massive moving masses.
Replacing the Airtac SI125 Standard Cylinder SI125X325 with the SAI125X325
To replace the SI125X325, order the SAI125X325. It drops directly into existing ISO 15552 fixtures with the same 125mm bore, 325mm stroke, G1/2 port, and M27x2 rod thread. Because this is a 325mm stroke, use external guides to prevent rod bending and side-load wear. If sizing alternatives, neighboring bores offer different force classes (100mm yields 3927N push; 160mm yields 10053N push at 0.5MPa). For load holding on air loss, note that a plain cylinder drifts; the 40mm air cushions only decelerate near stroke ends. Use an external pilot check valve or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X325
- ✓ 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 SI125X325 FAQ
Yes, the SI125X325 is discontinued. The direct replacement is the SAI125X325. It shares the identical ISO 15552 mounting interface, 125mm bore, 325mm stroke, force, and G1/2 port, fitting existing fixtures perfectly while adding an upgraded piston seal.
This double-acting cylinder uses a G1/2 port. It generates 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. It operates at 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X325
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X325 replacement — usually within 7-8 hours.