This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X50SN, 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 SI125X50SN
The AirTAC SI125 Standard Cylinder SI125X50SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 50mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X50SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke50 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X50SN
- 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 SI125X50SN
The AirTAC SI125X50SN is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 50 mm stroke, delivering 6136 N push force at 0.5 MPa. It featured an extruded aluminum barrel, a G1/2 port, and an NBR seal rated for -20 to +70 C. Because this SI model is end-of-life, you should order the direct replacement: SAI125X50SN. The SAI shares the same ISO 15552 mounting interface, bore, stroke, force, and port, fitting existing fixtures perfectly.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. Your -SN configuration includes a piston magnet for legacy CS1-B/DS1-B sensors. The SAI family also adds SAIL and BSAI lock variants absent from the SI line.
Airtac SI125 Standard Cylinder SI125X50SN Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X50SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X50SN |
| Bore size | Ø125 mm |
| Stroke | 50 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 SAI125X50SN 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 SAI125X50SN 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 SI125X50SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×50 | 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 SI125X50SN Is Used
Heavy Press Operations
Ideal for high-tonnage pressing and forming tasks requiring the full 6136 N push force at 0.5 MPa over a short 50 mm travel.
Industrial Mold Ejection
Provides robust ejection force for large injection molds, benefiting from the adjustable 40 mm air cushions at both ends.
Replacing the Airtac SI125 Standard Cylinder SI125X50SN with the SAI125X50SN
To replace the discontinued SI125X50SN, order the SAI125X50SN. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the 50 mm stroke, the G1/2 port, and the -SN magnet and NBR seal. If you need more force than the 6136 N at 0.5 MPa, the neighboring 160 mm bore offers 10053 N; if less is needed, the 100 mm bore provides 3927 N. Note that a plain cylinder drifts without live air; the cushion only decelerates. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variants. With its 50 mm stroke, side-load risks are minimal, but always guide the load.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X50SN
- ✓ 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 SI125X50SN FAQ
Yes, the SI125X50SN is discontinued. The direct replacement is the AirTAC SAI125X50SN. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 50 mm stroke, G1/2 port, and mounting interface.
The 125 mm bore yields 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s. It uses a G1/2 port and M27x2 rod thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X50SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X50SN replacement — usually within 7-8 hours.