This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X250S, 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 SI63X250S
The AirTAC Airtac SI63 Standard Cylinder SI63X250S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 250mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63X250S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke250 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63X250S
- 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 SI63X250S
The AirTAC SI63X250S is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 250mm stroke. It delivers 1559 N push force at 0.5 MPa via a G3/8 port. AirTAC replaced this legacy unit with the SAI63X250S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and porting.
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 variants the SI lacked, such as the SAIL air-released lock and BSAI clamp-lock, while the original -S magnet supports legacy CS1-B/DS1-B sensors.
Airtac SI63 Standard Cylinder SI63X250S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X250S |
| Bore size | Ø63 mm |
| Stroke | 250 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 SAI63X250S 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 SAI63X250S 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 SI63X250S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×250 | 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 SI63X250S Is Used
Clamping Actuators
Secures mid-weight machined parts in CNC fixtures using 1559 N of thrust at 0.5 MPa, ensuring rigid holding during metal removal.
Package Diversion
Drives 250mm stroke routing gates to redirect heavy pallets along processing lines, benefiting from the 30-800 mm/s speed range.
Replacing the Airtac SI63 Standard Cylinder SI63X250S with the SAI63X250S
To replace the SI63X250S, order the SAI63X250S and confirm the ISO 15552 mounting interface, 63mm bore, 250mm stroke, G3/8 port (PT/G/NPT), and your mounting accessory. The -S magnet allows use of legacy CS1-B/DS1-B switches, though the SAI replacement uses current AirTAC sensors. For sizing, the 63mm bore yields 1559 N push at 0.5 MPa; if less force is needed, a 50mm bore provides 982 N, or an 80mm bore offers 2513 N. Because the 250mm stroke is under 300mm, side-load risks are minimal, but always guide external loads. A plain cylinder drifts on air loss since cushions only decelerate; for load holding, specify the SAIL lock variant, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X250S
- ✓ 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 SI63X250S FAQ
Yes, the SI63X250S is discontinued. The direct replacement is the AirTAC SAI63X250S. It is dimensionally interchangeable per ISO 15552, matching the 63mm bore, 250mm stroke, output force, G3/8 port, and mounting accessories, so it fits existing fixtures directly.
The 63mm bore features a G3/8 air port and provides 1559 N push and 1402 N pull at 0.5 MPa. At 0.7 MPa it pushes 2182 N, and at 0.9 MPa it pushes 2805 N. The theoretical maximum force is 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X250S replacement — usually within 7-8 hours.