This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX150S, 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 SI125BX150S
The AirTAC SI125 Standard Cylinder SI125BX150S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 150mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX150S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke150 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX150S
- 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 SI125BX150S
The AirTAC SI125BX150S is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 150mm stroke. It features a SUS304 stainless steel piston rod (-B) and a built-in magnet (-S) for legacy CS1-B/DS1-B switches. Delivering 6136 N push force at 0.5 MPa through a G1/2 port, it is replaced by the SAI125BX150S.
The SAI125BX150S is the direct replacement, matching the ISO 15552 mounting interface, bore, stroke, force, and port. It uses an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI125 Standard Cylinder SI125BX150S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX150S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX150S |
| Bore size | Ø125 mm |
| Stroke | 150 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 SAI125BX150S 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 SAI125BX150S 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 SI125BX150S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×150 | 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 SI125BX150S Is Used
Heavy-Duty Pressing
Drives large stamping or forming dies requiring substantial thrust, utilizing the 6136 N push force at 0.5 MPa.
Pallet Handling
Actuates heavy load diverter arms or lift gates in automated storage systems where the SUS304 rod resists moisture.
Injection Molding Eject
Ejects large molded parts from heavy machinery, benefiting from the robust 125mm bore and adjustable 40mm cushions.
Replacing the Airtac SI125 Standard Cylinder SI125BX150S with the SAI125BX150S
To replace the SI125BX150S, order the SAI125BX150S. Confirm the ISO 15552 mounting interface, the 150mm stroke, the G1/2 port, and your mounting accessory. The -B rod is SUS304 stainless steel, and the -S magnet works with legacy CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). At 0.5 MPa this 125mm bore yields 6136 N push and 5734 N pull; if undersized, the 160mm bore offers 10053 N push. Note that a plain cylinder drifts without live air, as the cushion only decelerates. For load holding, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX150S
- ✓ 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 SI125BX150S FAQ
Yes, the SI125BX150S is discontinued. The direct replacement is the SAI125BX150S. It shares the same ISO 15552 mounting interface, 125mm bore, 150mm stroke, output force, and G1/2 port, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/2 port. It 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX150S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX150S replacement — usually within 7-8 hours.