This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X450N, 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 SI125X450N
The AirTAC SI125 Standard Cylinder SI125X450N 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 SAI125X450N, 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 → SAI125X450N
- 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 SI125X450N
The AirTAC SI125X450N is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 450 mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. The direct replacement is the SAI125X450N, matching the interface, force, and mounting.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. This SI unit lacks a magnet (-S) so it cannot accept CS1-B/DS1-B sensors. The NBR (-N) seal supports -20 to +70 C. For load holding, the cushion only decelerates; use SAIL or BSAI lock variants.
Airtac SI125 Standard Cylinder SI125X450N Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X450N |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X450N |
| 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 SAI125X450N 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 SAI125X450N 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 SI125X450N
| 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 SI125X450N Is Used
Heavy Stamping Press
Drives large platens and heavy dies using 6136 N thrust at 0.5 MPa, relying on the 40 mm adjustable cushions to absorb end-of-stroke impact.
Large Mold Clamping
Secures heavy industrial molds in place during processing, utilizing the NBR seals for standard -20 to +70 C factory environments.
Replacing the Airtac SI125 Standard Cylinder SI125X450N with the SAI125X450N
To replace the SI125X450N, order the SAI125X450N. Confirm the ISO 15552 mounting interface, 450 mm stroke, G1/2 port, and M27x2 rod thread. This non-magnet SKU cannot take a sensor; order an -S SAI if sensing is needed. At 0.5 MPa it pushes 6136 N (safe load ~3682 N); the neighboring 100 mm bore pushes 3927 N. For the 450 mm stroke, use external guides to prevent rod bending and side-load wear. The cushion only decelerates; for load holding on air loss, use the SAIL lock or a pilot check valve. Speed is 30-500 mm/s.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X450N
- ✓ 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 SI125X450N FAQ
Yes, the SI125X450N is discontinued. The direct replacement is the SAI125X450N. It is dimensionally interchangeable per ISO 15552, keeping the same 125 mm bore, 450 mm stroke, G1/2 port, and mounting fixtures.
It features a G1/2 port and M27x2 rod thread. Force output is 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 max of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X450N
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X450N replacement — usually within 7-8 hours.