This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX25, 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 SI125BX25
The AirTAC SI125 Standard Cylinder SI125BX25 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 25mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX25, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke25 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX25
- 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 SI125BX25
The AirTAC SI125BX25 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 25 mm stroke. Delivering 6136 N push force at 0.5 MPa, it features a SUS304 stainless steel rod and a G1/2 port. The direct replacement is the SAI125BX25, matching the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
This SAI upgrade introduces an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. Note that this specific SI125BX25 SKU lacks a magnet and cannot accept a position sensor.
Airtac SI125 Standard Cylinder SI125BX25 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX25 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX25 |
| Bore size | Ø125 mm |
| Stroke | 25 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 SAI125BX25 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 SAI125BX25 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 SI125BX25
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×25 | 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 SI125BX25 Is Used
Heavy Stamping Press
Provides the high 6136 N thrust at 0.5 MPa required to actuate heavy-duty stamping and forming presses, utilizing its short 25 mm stroke for rapid cycling.
Pallet Stopper Gate
Functions as a robust blocking gate on high-mass pallet conveyors, where the SUS304 stainless rod offers corrosion resistance in humid or wash-down environments.
Industrial Clamp Press
Applies sustained 8590 N clamping force at 0.7 MPa for holding large composite or metal components during secondary machining and assembly processes.
Replacing the Airtac SI125 Standard Cylinder SI125BX25 with the SAI125BX25
To replace the discontinued SI125BX25, order the SAI125BX25. Verify your ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/2 port thread (PT, G, or NPT), and the M27x2 rod-end thread. Because this SKU lacks a magnet (-S), it cannot support legacy CS1-B/DS1-B sensors; order an SAI variant with a magnet if position feedback is required. Sizing both ways: the 125 mm bore yields 6136 N push at 0.5 MPa, while the neighboring 100 mm bore offers 3927 N. For load holding on air loss, note that a standard cylinder drifts; the cushion only decelerates. Use an external pilot check valve, or explore the SAIL or BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX25
- ✓ 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 SI125BX25 FAQ
Yes, the AirTAC SI125BX25 is discontinued. The direct replacement is the SAI125BX25. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 25 mm stroke, force, G1/2 port, and mounting fixtures.
This double-acting cylinder features a G1/2 air port and an M27x2 rod thread. 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 maximum of 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX25
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX25 replacement — usually within 7-8 hours.