This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X450FA, 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 SI125X450FA
The AirTAC SI125 Standard Cylinder SI125X450FA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 450mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X450FA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke450 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X450FA
- 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 SI125X450FA
The AirTAC SI125X450FA is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 450 mm stroke, delivering 6136 N push force at 0.5 MPa. It features an FA flange mounting interface and a G1/2 air port. Because this legacy SI unit is end-of-life, you should order the direct replacement: SAI125X450FA. The SAI upgrade retains the identical ISO 15552 mounting dimensions, bore, stroke, force, and port, fitting your existing fixtures perfectly.
The SAI replacement introduces an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. Note that this specific SI125X450FA SKU lacks a magnet (-S), meaning it cannot accept position sensors like the legacy CS1-B or DS1-B switches.
Airtac SI125 Standard Cylinder SI125X450FA Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X450FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X450FA |
| Bore size | Ø125 mm |
| Stroke | 450 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 SAI125X450FA 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 SAI125X450FA 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 SI125X450FA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×450 | 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 SI125X450FA Is Used
Heavy Press Operations
Ideal for applying high clamping or forming pressure, utilizing the 6136 N push force at 0.5 MPa to secure heavy metal components during industrial stamping.
Automated Material Routing
Actuates heavy-duty diverter gates or sorting arms on high-capacity assembly lines, moving bulky goods reliably over the 450 mm travel distance.
Replacing the Airtac SI125 Standard Cylinder SI125X450FA with the SAI125X450FA
To replace the discontinued SI125X450FA, order the SAI125X450FA. Verify your ISO 15552 FA flange mounting, 125 mm bore, 450 mm stroke, and G1/2 port (available in PT, G, or NPT threads). The SAI family also adds variants the SI lacked, such as the SAIL air-released lock, SAIF built-in valve, and BSAI clamp-lock. If you need to hold a load without live air, note that a plain cylinder drifts when valve pressure is centered—the cushion only decelerates near stroke ends. Use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Because the 450 mm stroke is long, use external guides to prevent rod bending and side-load wear. If downsizing, a 100 mm bore yields 3927 N push at 0.5 MPa; if upsizing, a 160 mm bore yields 10053 N. The rod is Ø32 mm with an M27x2 thread, operating at 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X450FA
- ✓ 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 SI125X450FA FAQ
Yes, the AirTAC SI125X450FA is discontinued and end-of-life. The direct replacement is the SAI125X450FA. It is dimensionally interchangeable per the ISO 15552 standard, matching the 125 mm bore, 450 mm stroke, FA flange, and G1/2 port for a seamless fixture swap.
The 125 mm bore delivers 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N push at 0.9 MPa, and a theoretical maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s, with a 40 mm adjustable air cushion at both ends and a G1/2 air port.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X450FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X450FA replacement — usually within 7-8 hours.