This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX450SH, 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 SI125BX450SH
The AirTAC SI125 Standard Cylinder SI125BX450SH 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 SAI125BX450SH, 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 → SAI125BX450SH
- 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 SI125BX450SH
The AirTAC SI125BX450SH is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 450mm stroke. This legacy unit delivers 6136N push force at 0.5MPa, features a SUS304 stainless piston rod, a Viton H high-temperature seal rated for 0-150C, and a G1/2 port. AirTAC replaced it with the SAI125BX450SH, a direct replacement sharing the exact ISO 15552 mounting interface, bore, stroke, force and port.
The SAI upgrade introduces an advanced piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also adds SAIL, SAIF and BSAI lock variants absent from the SI line. Your existing CS1-B/DS1-B sensors will fit the magnet, though current AirTAC switches are used on the SAI.
Airtac SI125 Standard Cylinder SI125BX450SH Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX450SH |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX450SH |
| 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 SAI125BX450SH 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 SAI125BX450SH 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 SI125BX450SH
| 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 SI125BX450SH Is Used
Heavy Stamping Press
Drives large platens and heavy dies requiring 6136N push at 0.5MPa, utilizing the 450mm stroke for deep-draw operations.
High-Tact Foundry Gate
Operates large access doors near hot zones, leveraging the Viton H seal to withstand ambient temperatures up to 150C.
Replacing the Airtac SI125 Standard Cylinder SI125BX450SH with the SAI125BX450SH
To replace the SI125BX450SH, order the SAI125BX450SH. Confirm the ISO 15552 mounting interface, the 450mm stroke, the G1/2 port, and your specific mounting accessory (LB, FA, CA, TC, etc.). The S and H suffixes mean you must specify the magnet and Viton high-temp seal. If sizing up or down, neighbouring bores are 100mm and 160mm; at 0.5MPa the 100mm bore yields 3927N push, while the 160mm bore yields 10053N. Because this is a 450mm stroke, use an external guide to prevent rod bending and side-load damage. A plain cylinder does not hold load on air loss—the cushion only decelerates—so for suspended loads use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX450SH
- ✓ 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 SI125BX450SH FAQ
Yes, the SI125BX450SH is discontinued. The direct replacement is the SAI125BX450SH. It is dimensionally interchangeable per ISO 15552, matching the 125mm bore, 450mm stroke, 6136N force, G1/2 port, and mounting interface.
This 125mm bore cylinder has a G1/2 port. The force ratings are: 6136N push and 5734N pull at 0.5MPa; 8590N push at 0.7MPa; 11045N push at 0.9MPa; and a theoretical max of 1251kgf at 1.0MPa. Speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX450SH
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX450SH replacement — usually within 7-8 hours.