This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125BX210, 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 SI125BX210
The AirTAC SI125 Standard Cylinder SI125BX210 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 210mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125BX210, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke210 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125BX210
- 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 SI125BX210
The AirTAC SI125BX210 is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 210 mm stroke. It delivers 6136 N push and 5734 N pull at 0.5 MPa, utilizing a G1/2 air port and a SUS304 stainless steel piston rod (B option) for corrosion resistance. AirTAC replaced this legacy unit with the SAI125BX210, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. Note that this specific SKU lacks a magnet and cannot accept position sensors.
Airtac SI125 Standard Cylinder SI125BX210 Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125BX210 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125BX210 |
| Bore size | Ø125 mm |
| Stroke | 210 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 SAI125BX210 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 SAI125BX210 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 SI125BX210
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×210 | 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 SI125BX210 Is Used
Heavy Press Clamping
Ideal for securing heavy metal components during machining, using the 6136 N push force at 0.5 MPa to hold parts rigidly against tool vibration.
Pallet Lift Stations
Drives vertical lifting arms for loaded pallets, safely managing a 313 kg lift margin while benefiting from the corrosion-resistant SUS304 rod in humid settings.
Bulk Material Diversion
Actuates heavy-duty diverter gates on high-capacity conveyor lines, relying on the robust 125 mm bore and 210 mm stroke to shift dense product flows.
Replacing the Airtac SI125 Standard Cylinder SI125BX210 with the SAI125BX210
To replace the discontinued SI125BX210, order the SAI125BX210. Confirm the ISO 15552 mounting interface, the 125 mm bore, 210 mm stroke, G1/2 port (PT/G/NPT thread options), and your specific mounting accessory. This unit uses a SUS304 stainless rod (B option) and lacks a magnet (-S), meaning it cannot support CS1-B/DS1-B sensors. When sizing, a 100 mm bore offers 3927 N push at 0.5 MPa, while a 160 mm bore provides 10053 N. For load holding, note that a plain cylinder drifts on air loss; the air cushion only decelerates near stroke end. Use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125BX210
- ✓ 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 SI125BX210 FAQ
Yes, the AirTAC SI125BX210 is discontinued. The direct replacement is the SAI125BX210. It shares the exact ISO 15552 mounting interface, 125 mm bore, 210 mm stroke, G1/2 port, and output force, fitting directly into existing fixtures.
The 125 mm bore features a G1/2 air port and an M27x2 rod thread. At 0.5 MPa it provides 6136 N push and 5734 N pull. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum force is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125BX210
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125BX210 replacement — usually within 7-8 hours.