This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX240, 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 SI125BX240
The AirTAC SI125 Standard Cylinder SI125BX240 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 240mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX240, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke240 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX240
- 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 SI125BX240
The AirTAC SI125BX240 is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore, 240mm stroke, and a SUS304 stainless steel rod. It delivers 6136 N push and 5734 N pull at 0.5 MPa. The direct replacement is the SAI125BX240, matching the ISO 15552 mounting interface, bore, force, G1/2 port, and stroke.
The SAI upgrade utilizes an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This SKU lacks a magnet (-S), so it cannot accept a CS1-B/DS1-B sensor. The cushion only decelerates; use SAIL or BSAI variants for load holding.
Airtac SI125 Standard Cylinder SI125BX240 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX240 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX240 |
| Bore size | Ø125 mm |
| Stroke | 240 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 SAI125BX240 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 SAI125BX240 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 SI125BX240
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×240 | 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 SI125BX240 Is Used
Heavy Stamping Press
Drives heavy-duty stamping actuators where the 6136 N push force at 0.5 MPa easily overcomes die resistance.
Washdown Ejector
Ejects parts from humid or washdown environments utilizing the SUS304 stainless rod for corrosion resistance.
Replacing the Airtac SI125 Standard Cylinder SI125BX240 with the SAI125BX240
To replace the SI125BX240, order the SAI125BX240. Confirm the ISO 15552 mounting interface, 125mm bore, 240mm stroke, G1/2 port (PT/G/NPT thread options), and your specific mounting accessory. Because this is the -B SUS304 stainless rod option, specify it to maintain corrosion resistance instead of the default carbon steel. This SKU has no magnet, meaning it cannot support CS1-B/DS1-B switches. For sizing, the 125mm bore yields 6136 N push at 0.5 MPa; dropping to an 80mm bore gives 2513 N, while 160mm provides 10053 N. For load holding on air loss, a plain cylinder drifts; add an external rod lock or pilot check valve, or use the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX240
- ✓ 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 SI125BX240 FAQ
Yes, the SI125BX240 is discontinued. The direct replacement is the SAI125BX240, which is dimensionally interchangeable per ISO 15552. It maintains the same 125mm bore, 240mm stroke, 6136 N force, G1/2 port, and mounting interface.
This 125mm bore cylinder features a G1/2 air port, M27x2 rod thread, and 40mm adjustable cushions. 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 max of 1251 kgf at 1.0 MPa. Speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX240
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX240 replacement — usually within 7-8 hours.