This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X210SFA, 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 SI125X210SFA
The AirTAC Airtac SI125 Standard Cylinder SI125X210SFA 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 SAI125X210SFA, 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 → SAI125X210SFA
- 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 SI125X210SFA
The AirTAC SI125X210SFA is a discontinued double-acting ISO 15552 profile cylinder with a 125mm bore and 210mm stroke. It delivers 6136N push and 5734N pull force at 0.5MPa, utilizing a G1/2 port and an FA flange mounting interface. AirTAC replaced this legacy unit with the SAI125X210SFA, a direct upgrade retaining the exact ISO 15552 mounting dimensions, bore, stroke, output 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. The SAI family also introduces lock and clamp variants (SAIL, BSAI) absent in the SI line. Your -S suffix indicates a piston magnet for CS1-B/DS1-B sensors, though the SAI equivalent uses current AirTAC switches.
Airtac SI125 Standard Cylinder SI125X210SFA Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X210SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X210SFA |
| 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 SAI125X210SFA 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 SAI125X210SFA 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 SI125X210SFA
| 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 SI125X210SFA Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136N push force at 0.5MPa to maintain rigid clamping without deflection.
Bulk Material Diversion
Drives large-scale package diverters on high-throughput sorting lines, where the 125mm bore and 210mm stroke easily move heavy palletized goods.
Replacing the Airtac SI125 Standard Cylinder SI125X210SFA with the SAI125X210SFA
To replace the SI125X210SFA, order the SAI125X210SFA. Confirm the ISO 15552 interface, 125mm bore, 210mm stroke, G1/2 port, and FA flange mount. The -S magnet is retained for position sensing, but you must update from legacy CS1-B/DS1-B switches to current AirTAC equivalents. When sizing, neighboring bores offer different force classes: a 100mm bore provides 3927N push at 0.5MPa, while a 160mm bore yields 10053N. At 0.7MPa this 125mm unit pushes 8590N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants. With a 210mm stroke, ensure adequate guide support to prevent rod bending and side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X210SFA
- ✓ 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 SI125X210SFA FAQ
Yes, the SI125X210SFA is discontinued. The direct replacement is the SAI125X210SFA. It shares the same ISO 15552 mounting interface, 125mm bore, 210mm stroke, output force, G1/2 port, and FA flange mount, fitting directly into existing fixtures.
This double-acting cylinder uses 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 maximum of 1251 kgf at 1.0 MPa. Operating speed is 30-500 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X210SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X210SFA replacement — usually within 7-8 hours.