This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI125X63S, 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 SI125X63S
The AirTAC SI125 Standard Cylinder SI125X63S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø125mm bore and 63mm stroke, G1/2 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI125X63S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ125 mm
- Stroke63 mm
- Port sizeG1/2
- Acting typeDouble acting
- Rod threadM27×2.0
- StatusDiscontinued → SAI125X63S
- 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 SI125X63S
The AirTAC SI125X63S is a discontinued double-acting ISO 15552 profile cylinder with a 125 mm bore and 63 mm stroke. Delivering 6136 N push force at 0.5 MPa via a G1/2 port, it is replaced by the SAI125X63S. This direct upgrade shares the exact ISO 15552 mounting interface, bore, stroke, force, port and accessories.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SI line lacked lock variants, but the SAI family adds SAIL and BSAI clamp options. The -S suffix means a piston magnet for CS1-B/DS1-B sensors.
Airtac SI125 Standard Cylinder SI125X63S Technical Specifications
| Model | Airtac SI125 Standard Cylinder SI125X63S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI125X63S |
| Bore size | Ø125 mm |
| Stroke | 63 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 SAI125X63S 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 SAI125X63S 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 SI125X63S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 125 | Bore size in mm. |
| ×63 | 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 SI125X63S Is Used
Heavy Press Clamping
Secures large metal castings during machining operations, utilizing the 6136 N push force at 0.5 MPa to hold components rigidly against the tool path.
Pallet Handling Gates
Actuates heavy-duty routing gates in automated distribution centers, where the robust 125 mm bore and 63 mm stroke endure constant high-impact cycling.
Injection Mould Ejection
Drives the ejection plate of mid-size plastic moulding machines, requiring the reliable 5734 N pull force to extract dense fabricated parts cleanly.
Replacing the Airtac SI125 Standard Cylinder SI125X63S with the SAI125X63S
To replace the SI125X63S, order the SAI125X63S. Verify the ISO 15552 mounting accessory (LB, FA, CA, TC), the G1/2 port thread (PT, G or NPT), and the -S magnet for CS1-B/DS1-B switches. If you need more force, the 160 mm bore offers 10053 N push at 0.5 MPa; if less is needed, the 100 mm bore provides 3927 N. A plain cylinder drifts on air loss, so for load holding use the SAIL lock, BSAI clamp-lock, or an external pilot check valve. The SAI also adds the SAIF valve variant for bores 32-100.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI125X63S
- ✓ 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 SI125X63S FAQ
Yes, the SI125X63S is discontinued. The direct replacement is the SAI125X63S. It is dimensionally interchangeable per ISO 15552, retaining the same 125 mm bore, 63 mm stroke, 6136 N output force, G1/2 port and mounting interface.
This double-acting cylinder operates at 30-500 mm/s. 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. The G1/2 port and M27x2 rod thread handle these heavy loads.
Related AirTAC SAI Cylinders
Request a Quote for the SAI125X63S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI125X63S replacement — usually within 7-8 hours.