This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X1250S, 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 SI63 Standard Cylinder SI63X1250S
The AirTAC Airtac SI63 Standard Cylinder SI63X1250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 1250mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63X1250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke1250 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63X1250S
- 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 SI63 Standard Cylinder SI63X1250S
The AirTAC SI63X1250S is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore and 1250 mm stroke. It delivers 1559 N push force at 0.5 MPa through a G3/8 port. AirTAC replaced this legacy unit with the SAI63X1250S, a direct upgrade sharing the exact ISO 15552 mounting interface, bore, stroke, force and port size. The SAI features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life.
Because this is a -S model, it includes a piston magnet for legacy CS1-B/DS1-B sensors (the SAI replacement uses current AirTAC switches). The SAI family also introduces variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock. Note that a standard cylinder does not hold load without live air; the cushion only decelerates. For load holding, use the SAIL/BSAI variants or an external pilot check valve. At 1250 mm, this long stroke requires external guides to prevent rod bending.
Airtac SI63 Standard Cylinder SI63X1250S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X1250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X1250S |
| Bore size | Ø63 mm |
| Stroke | 1250 mm |
| Acting type | Double acting |
| Port size | G3/8 |
| Rod thread | M16×1.5 |
| 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 – 800 mm/s |
| Cushion | Adjustable, 30 mm |
| Max standard stroke | Up to 1500 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI63X1250S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø63mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 1559 N | 1402 N |
| 0.7 MPa | 2182 N | — |
| Max (@1.0 MPa) | 318 kgf | |
The SAI63X1250S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI63 Standard Cylinder SI63X1250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×1250 | 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 SI63 Standard Cylinder SI63X1250S Is Used
Long-Stroke Transfer
Pushes heavy pallets 1250 mm between conveyor zones using 1559 N of thrust at 0.5 MPa, guided externally to prevent rod bending.
Large Door Actuation
Opens 1.25-meter machine safety doors, utilizing the G3/8 port and 30 mm adjustable cushions to soften end-of-stroke impact.
Replacing the Airtac SI63 Standard Cylinder SI63X1250S with the SAI63X1250S
To replace the discontinued SI63X1250S, order the SAI63X1250S. It drops directly into existing fixtures via the ISO 15552 mounting interface, preserving the 63 mm bore, 1250 mm stroke, M16x1.5 rod thread, G3/8 port, and -S magnet for position sensing. When sizing, consider neighboring bores: a 50 mm bore yields 982 N push at 0.5 MPa, while an 80 mm bore provides 2513 N. If your application requires load holding on air loss, do not rely on the standard cushions; instead, specify the SAIL lock or BSAI clamp-lock variant, or fit an external rod lock. Because the 1250 mm stroke exceeds 300 mm, you must use external guide rails to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X1250S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI63 Standard Cylinder SI63X1250S FAQ
Yes, the SI63X1250S is discontinued. The direct replacement is the AirTAC SAI63X1250S. It shares the identical ISO 15552 mounting interface, 63 mm bore, 1250 mm stroke, output force, and G3/8 port, fitting existing fixtures perfectly while upgrading the piston seal.
The 63 mm bore uses a G3/8 air port. Force ratings are 1559 N push and 1402 N pull at 0.5 MPa, 2182 N push at 0.7 MPa, 2805 N push at 0.9 MPa, and a theoretical maximum of 318 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X1250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X1250S replacement — usually within 7-8 hours.