This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X25FA, 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 SI125X25FA
The AirTAC Airtac SI125 Standard Cylinder SI125X25FA 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 SAI125X25FA, 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 → SAI125X25FA
- 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 SI125X25FA
The AirTAC SI125X25FA is a discontinued double-acting ISO 15552 profile cylinder with an FA flange mount. Built for heavy thrust, it delivers 6136 N push at 0.5 MPa through a 125 mm bore and G1/2 port. The direct replacement is the SAI125X25FA, matching the exact stroke, force, and mounting interface.
Upgrading to the SAI125X25FA retains the ISO 15552 footprint while adding an upgraded piston seal (two Y-shaped one-way elements for low start-up pressure). For load holding, note a plain cylinder drifts on air loss; use the SAIL or BSAI lock variants if needed. This non-magnet SKU cannot take a sensor.
Airtac SI125 Standard Cylinder SI125X25FA Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X25FA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X25FA |
| 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 SAI125X25FA 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 SAI125X25FA 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 SI125X25FA
| 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 SI125X25FA Is Used
Rigid Clamping Fixture
Secures large fabricated components via the FA flange mount, delivering 5734 N of pull force at 0.5 MPa to hold parts rigidly during machining.
Short-Stroke Pressing
Performs high-impact seating of bearings or pins, leveraging the 11045 N output at 0.9 MPa within a compact 25 mm displacement range.
Replacing the Airtac SI125 Standard Cylinder SI125X25FA with the SAI125X25FA
To replace the SI125X25FA, order the SAI125X25FA. Verify the ISO 15552 FA flange interface, 125 mm bore, 25 mm stroke, and G1/2 port (PT/G/NPT thread options). Because this SKU lacks the -S magnet, it cannot accept CS1-B/DS1-B sensors; order a magnet-equipped SAI if position detection is required. For sizing, a 100 mm bore yields 3927 N push at 0.5 MPa, while a 160 mm bore yields 10053 N. The 125 mm bore provides 8590 N at 0.7 MPa. The 25 mm stroke avoids rod-bending side-load risks seen in longer strokes. Remember the air cushion only decelerates; it does not hold load. For secure holding, select the SAIL (air-released lock) or BSAI (clamp-lock) variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X25FA
- ✓ 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 SI125X25FA FAQ
Yes, the SI125X25FA is discontinued. The direct replacement is the AirTAC SAI125X25FA. It is dimensionally interchangeable per ISO 15552, matching the 125 mm bore, 25 mm stroke, G1/2 port, and FA flange mount.
The G1/2 port feeds a 125 mm bore yielding 6136 N push and 5734 N pull at 0.5 MPa. At 0.7 MPa push is 8590 N, and at 0.9 MPa it is 11045 N. The theoretical maximum is 1251 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X25FA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X25FA replacement — usually within 7-8 hours.