This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X250, 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 SI63X250
The AirTAC Airtac SI63 Standard Cylinder SI63X250 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 SAI63X250, 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 → SAI63X250
- 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 SI63X250
The AirTAC SI63X250 is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore and 250 mm stroke. It delivers 1559 N push force at 0.5 MPa through a G3/8 port. AirTAC replaced this legacy unit with the SAI63X250, a direct upgrade retaining the exact interface, M16x1.5 rod thread and 30 mm cushions.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure and longer life. For applications needing load holding on air loss, the new SAIL or BSAI lock variants solve what the plain SI could not.
Airtac SI63 Standard Cylinder SI63X250 Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X250 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X250 |
| 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 SAI63X250 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 SAI63X250 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 SI63X250
| 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 SI63X250 Is Used
Package Diverting
Drives diverter arms on sorting lines, using the 1559 N force to push parcels reliably at cycling speeds within the 30-800 mm/s range.
Clamp Actuation
Secures mid-weight workpieces in machining fixtures, providing stable holding via the 63 mm bore during drilling or milling operations.
Replacing the Airtac SI63 Standard Cylinder SI63X250 with the SAI63X250
To replace the SI63X250, order the SAI63X250 keeping the identical ISO 15552 mounting dimensions, 250 mm stroke, G3/8 port and accessories. This non-magnet SKU cannot accept a sensor; if position detection is needed, select an SAI model with the -S magnet option and current AirTAC switches. For sizing, the neighbouring 50 mm bore yields 982 N push @0.5 MPa, while the 80 mm bore provides 2513 N. Note that a plain cylinder drifts without live air—the cushion only decelerates near stroke end—so use a pilot check valve or SAIL lock for holding. At 250 mm stroke, guide external rods to prevent side-load bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X250
- ✓ 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 SI63X250 FAQ
Yes, the SI63X250 is discontinued. The direct replacement is the AirTAC SAI63X250. It is dimensionally interchangeable per ISO 15552, retaining the same 63 mm bore, 250 mm stroke, output force, G3/8 port and mounting interface, but adds an upgraded piston seal.
The 63 mm bore uses a G3/8 air port. It generates 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.
Request a Quote for the SAI63X250
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X250 replacement — usually within 7-8 hours.