This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX45, 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 SI125BX45
The AirTAC Airtac SI125 Standard Cylinder SI125BX45 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 45mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX45, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke45 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX45
- 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 SI125BX45
The AirTAC SI125BX45 is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 45mm stroke. It delivers 6136 N push force at 0.5 MPa via a G1/2 port. AirTAC replaced it with the SAI125BX45 direct upgrade, sharing the exact ISO 15552 mounting interface, force, and dimensions.
The SAI upgrade features an improved piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU uses a SUS304 stainless steel rod (B-option) but lacks a magnet, so it cannot take CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125BX45 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX45 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX45 |
| Bore size | Ø125 mm |
| Stroke | 45 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 SAI125BX45 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 SAI125BX45 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 SI125BX45
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×45 | 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 SI125BX45 Is Used
Heavy Stamping Clamp
Secures thick steel plates in a press bed using 6136 N of clamping force at 0.5 MPa, with the SUS304 rod resisting coolant spray.
Pallet Stopper Gate
Acts as a robust 125mm bore stop gate for heavy-loaded roller conveyors, absorbing kinetic impact without needing a magnet sensor.
Injection Mold Ejector
Provides a short 45mm ejection stroke for large injection-molded parts, dropping directly into existing ISO 15552 fixture holes.
Replacing the Airtac SI125 Standard Cylinder SI125BX45 with the SAI125BX45
To replace the SI125BX45, order the SAI125BX45. Confirm the ISO 15552 mounting interface, 45mm stroke, and G1/2 port. This non-magnet SKU cannot accept position sensors; if sensing is needed, order an SAI with the S suffix. The SUS304 stainless rod suits corrosive environments. For sizing, the 100mm bore yields 3927 N push at 0.5 MPa, while the 160mm bore yields 10053 N. This cylinder does not hold load without air; use a pilot check valve or the SAIL/BSAI lock variant for hold. Stroke is under 300mm, so rod-bending side-load risks are minimal.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX45
- ✓ 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 SI125BX45 FAQ
Yes, the AirTAC SI125BX45 is discontinued. The direct replacement is the SAI125BX45. It is dimensionally interchangeable per ISO 15552, retaining the same 125mm bore, 45mm stroke, G1/2 port, and mounting interface.
The G1/2 port feeds a cylinder producing 6136 N push and 5734 N pull at 0.5 MPa, 8590 N push at 0.7 MPa, 11045 N at 0.9 MPa, and a theoretical max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX45
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX45 replacement — usually within 7-8 hours.