This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX750S, 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 SI125BX750S
The AirTAC SI125 Standard Cylinder SI125BX750S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 750mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX750S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke750 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX750S
- 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 SI125BX750S
The AirTAC SI125BX750S is a discontinued double-acting ISO 15552 profile cylinder featuring a 125mm bore and 750mm stroke. It delivers 6136N push force at 0.5MPa and uses a G1/2 port. The direct replacement is the SAI125BX750S, matching the exact ISO 15552 mounting interface, stroke, force, and accessories. The B suffix indicates a SUS304 stainless piston rod for corrosion resistance.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. For load holding, note that standard cylinders drift without live air; the cushion only decelerates. Use the SAIL or BSAI lock variants if needed.
Airtac SI125 Standard Cylinder SI125BX750S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX750S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX750S |
| Bore size | Ø125 mm |
| Stroke | 750 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 SAI125BX750S 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 SAI125BX750S 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 SI125BX750S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×750 | 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 SI125BX750S Is Used
Heavy Press Clamping
Secures large steel fabrications in a machining fixture, using the 6136N push force to hold parts rigidly against cutting loads.
Pallet Transfer
Drives a 750mm stroke pusher arm to index heavy pallets along a conveyor, requiring external guides to manage the long rod extension.
Stamping Ejection
Ejects thick metal blanks from a hydraulic press, benefiting from the SUS304 stainless rod in environments with cutting fluid spray.
Replacing the Airtac SI125 Standard Cylinder SI125BX750S with the SAI125BX750S
To replace the SI125BX750S, order the SAI125BX750S. Verify the ISO 15552 mounting interface, 750mm stroke, G1/2 port, and SUS304 rod. The -S magnet works with legacy CS1-B/DS1-B sensors. Sizing both ways: a 100mm bore gives 3927N push at 0.5MPa, while a 160mm bore yields 10053N. At 0.7MPa this 125mm bore reaches 8590N. For the 750mm stroke, use external guides to prevent rod bending and side loads. For load holding on air loss, add an external pilot check valve or choose the SAIL/BSAI lock variant, as cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX750S
- ✓ 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 SI125BX750S FAQ
Yes, the SI125BX750S is discontinued. The direct replacement is the SAI125BX750S. It features the same ISO 15552 mounting interface, 125mm bore, 750mm stroke, G1/2 port, and output force, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/2 port. It generates 6136N push and 5734N pull at 0.5MPa, 8590N push at 0.7MPa, 11045N push at 0.9MPa, and a theoretical max of 1251kgf at 1.0MPa. The operating speed is 30-500mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX750S
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