This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X450H, 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 SI125X450H
The AirTAC SI125 Standard Cylinder SI125X450H 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 SAI125X450H, 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 → SAI125X450H
- 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 SI125X450H
The AirTAC SI125X450H is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 450 mm stroke. This legacy unit delivers 6136 N push force at 0.5 MPa and features a G1/2 port with a 32 mm rod. It is replaced by the SAI125X450H.
The SAI125X450H is a direct replacement, matching the ISO 15552 mounting interface, bore, output force, and port size. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Because this SKU lacks a magnet (-S), it cannot take a sensor. The -H seal specifies Viton H for 0-150 C heat.
Airtac SI125 Standard Cylinder SI125X450H Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X450H |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X450H |
| 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 SAI125X450H 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 SAI125X450H 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 SI125X450H
| 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 SI125X450H Is Used
Heavy Machinery Forming
Drives large press beds and forming dies requiring substantial 6136 N push force over a 450 mm displacement.
Automated Clamp Fixtures
Secures large automotive or structural components during machining using the 125 mm bore's high clamping force.
Replacing the Airtac SI125 Standard Cylinder SI125X450H with the SAI125X450H
To replace the SI125X450H, order the SAI125X450H. Confirm the ISO 15552 mounting interface, the G1/2 port, the M27x2 rod thread, and your specific mounting accessory (LB, FA, TC, etc.). Since this SKU has no magnet, it cannot accept a CS1-B/DS1-B sensor; order an -S variant if sensing is needed. Sizing both ways: the 125 mm bore yields 6136 N push at 0.5 MPa, while the neighbouring 100 mm bore offers 3927 N. For a 450 mm stroke, use external guides to prevent rod bending and side-load wear. A plain cylinder drifts without air; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X450H
- ✓ 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 SI125X450H FAQ
Yes, the SI125X450H is discontinued. The direct replacement is the SAI125X450H. It shares the exact same ISO 15552 mounting interface, 125 mm bore, 450 mm stroke, output force, and G1/2 port, fitting directly into existing fixtures.
The bore is 125 mm with a G1/2 port. At 0.5 MPa it provides 6136 N push and 5734 N pull. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical max force is 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X450H
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X450H replacement — usually within 7-8 hours.