This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X20, 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 SI125X20
The AirTAC SI125 Standard Cylinder SI125X20 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 20mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X20, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke20 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X20
- 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 SI125X20
The AirTAC SI125X20 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 20 mm stroke, delivering 6136 N push force at 0.5 MPa. AirTAC replaced it with the SAI125X20, a direct upgrade retaining the exact ISO 15552 mounting interface, G1/2 port, and output force.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note this specific SKU lacks a magnet and cannot accept position sensors.
Airtac SI125 Standard Cylinder SI125X20 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X20 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X20 |
| Bore size | Ø125 mm |
| Stroke | 20 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 SAI125X20 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 SAI125X20 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 SI125X20
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×20 | 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 SI125X20 Is Used
Heavy-Duty Pressing
Ideal for applying high clamping or stamping force in automated machinery where a short, robust 20 mm stroke is needed.
Industrial Ejector
Provides powerful ejection of finished parts from molds or presses, utilizing the 6136 N push force at 0.5 MPa.
Replacing the Airtac SI125 Standard Cylinder SI125X20 with the SAI125X20
To replace the SI125X20, order the SAI125X20. Verify your ISO 15552 mounting hardware (LB, FA, CA, TC, etc.), the G1/2 air port, and the M27x2 rod thread. Because this non-magnetic SKU lacks a sensor groove piston ring, it cannot hold a switch; if sensing is required, order an SAI125X20-S. For sizing context, dropping to a 100 mm bore reduces push force to 3927 N at 0.5 MPa, while staying at 125 mm but increasing pressure to 0.7 MPa yields 8590 N. If the application requires load holding on air loss, note that the standard cushion only decelerates the piston; you must integrate an external pilot check valve, a rod lock, or switch to the SAIL or BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X20
- ✓ 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 SI125X20 FAQ
Yes, the SI125X20 is discontinued. The direct replacement is the AirTAC SAI125X20. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 20 mm stroke, G1/2 port, and mounting fixtures.
The G1/2 port is fixed by the 125 mm bore. At 0.5 MPa it provides 6136 N push and 5734 pull force. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X20
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X20 replacement — usually within 7-8 hours.