This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX40, 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 SI125BX40
The AirTAC Airtac SI125 Standard Cylinder SI125BX40 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 40mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX40, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke40 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX40
- 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 SI125BX40
The AirTAC SI125BX40 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 40 mm stroke. It delivers 6136 N push force at 0.5 MPa and features a SUS304 stainless piston rod for corrosion resistance. The direct replacement is the SAI125BX40, matching the G1/2 port, M27x2 thread, and 30-500 mm/s speed.
Upgrading to the SAI brings a new two Y-shaped one-way piston seal for low start-up pressure. Note this SKU lacks a magnet, so it cannot accept CS1-B/DS1-B sensors. For load holding, the cushion only decelerates; use a SAIL lock or external pilot check valve.
Airtac SI125 Standard Cylinder SI125BX40 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX40 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX40 |
| Bore size | Ø125 mm |
| Stroke | 40 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 SAI125BX40 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 SAI125BX40 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 SI125BX40
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×40 | 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 SI125BX40 Is Used
Pallet Localization
Shifts heavy loaded pallets into exact position on a conveyor line, relying on the 40 mm stroke and 125 mm bore for high-force clamping.
Injection Mold Ejection
Ejects dense molded parts from heavy tooling, utilizing the 40 mm cushioned stroke and robust 125 mm profile barrel for reliable operation.
Replacing the Airtac SI125 Standard Cylinder SI125BX40 with the SAI125BX40
To replace the SI125BX40, order the SAI125BX40. It is dimensionally interchangeable per the ISO 15552 mounting interface, keeping the exact 125 mm bore, 40 mm stroke, and G1/2 port. Because this specific SKU lacks the -S magnet, it cannot support position sensing; if switches are needed, select an SAI125X40S and use current AirTAC sensors. The -B rod specifies SUS304 stainless steel, ideal for moist environments compared to the standard carbon steel rod. For sizing, a 100 mm bore yields 3927 N at 0.5 MPa, while a 160 mm bore provides 10053 N. If the application requires holding a load without live air, the plain cylinder will drift; specify the SAIL air-released lock, the BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX40
- ✓ 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 SI125BX40 FAQ
Yes, the AirTAC SI125BX40 is discontinued. The direct replacement is the SAI125BX40. It shares the same ISO 15552 mounting interface, 125 mm bore, 40 mm stroke, G1/2 port, and output force, fitting directly into existing fixtures.
The 125 mm bore uses a G1/2 air port. At 0.5 MPa it provides 6136 N push and 5734 pull force. At 0.7 MPa push is 8590 N, at 0.9 MPa it is 11045 N, and the theoretical maximum is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX40
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX40 replacement — usually within 7-8 hours.