This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX120, 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 SI125BX120
The AirTAC SI125 Standard Cylinder SI125BX120 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 120mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX120, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke120 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX120
- 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 SI125BX120
The AirTAC SI125BX120 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 120 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa, utilizing a G1/2 port and an M27x2 rod thread. The direct replacement is the SAI125BX120, matching the bore, stroke, force, port, and ISO 15552 mounting interface exactly.
The SAI upgrade features a revised piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. This specific SKU uses a SUS304 stainless steel rod (-B) for corrosion resistance and lacks a magnet, so it cannot accept position switches.
Airtac SI125 Standard Cylinder SI125BX120 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX120 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX120 |
| Bore size | Ø125 mm |
| Stroke | 120 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 SAI125BX120 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 SAI125BX120 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 SI125BX120
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×120 | 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 SI125BX120 Is Used
Heavy Pressing Operations
Applies 6136 N of thrust at 0.5 MPa for securing heavy components or actuating large industrial presses.
Stainless Rod Tooling
The SUS304 rod option provides corrosion resistance for machining environments exposed to coolants.
Replacing the Airtac SI125 Standard Cylinder SI125BX120 with the SAI125BX120
To replace the SI125BX120, order the SAI125BX120. Confirm the ISO 15552 mounting interface, 120 mm stroke, G1/2 port, and your specific mounting accessory (LB, FA, TC, etc.). Because this SKU has no -S magnet, it cannot support legacy CS1-B/DS1-B sensors; if sensing is needed, specify a magnet on the SAI order. For load holding, note that a standard cylinder drifts on air loss—the cushion only decelerates—so add an external rod lock, pilot check valve, or use the SAIL/BSAI lock variant. If exploring neighbouring bores, the 100 mm bore yields 3927 N push, while the 160 mm bore yields 10053 N at 0.5 MPa.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX120
- ✓ 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 SI125BX120 FAQ
Yes, the SI125BX120 is discontinued. The direct replacement is the SAI125BX120, which shares the same ISO 15552 mounting interface, 125 mm bore, 120 mm stroke, output force, and G1/2 port.
The G1/2 port bore delivers 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 maximum theoretical force of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX120
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX120 replacement — usually within 7-8 hours.