This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X250SFTC, 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 SI63X250SFTC
The AirTAC Airtac SI63 Standard Cylinder SI63X250SFTC 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 SAI63X250SFTC, 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 → SAI63X250SFTC
- 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 SI63X250SFTC
The AirTAC SI63X250SFTC 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 SAI63X250SFTC, a direct upgrade retaining the exact ISO 15552 mounting interface, FTC trunnion, and M16x1.5 rod thread.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It also adds SAIL, SAIF, and BSAI variants absent from the SI line. The built-in magnet supports CS1-B/DS1-B sensors, and Viton H seals can raise the temperature limit to 150 C.
Airtac SI63 Standard Cylinder SI63X250SFTC Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X250SFTC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X250SFTC |
| 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 SAI63X250SFTC 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 SAI63X250SFTC 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 SI63X250SFTC
| 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 SI63X250SFTC Is Used
Clamping Fixtures
Secures mid-weight workpieces on machining lines, utilizing the 1559 N push force at 0.5 MPa to hold parts firmly during milling or drilling operations.
Package Diverting
Actuates diverter arms on sorting conveyors, where the 250 mm stroke provides the reach needed to redirect parcels between adjacent belts.
Replacing the Airtac SI63 Standard Cylinder SI63X250SFTC with the SAI63X250SFTC
To replace the SI63X250SFTC, order the SAI63X250SFTC. Confirm the ISO 15552 interface, 63 mm bore, 250 mm stroke, G3/8 port, FTC trunnion mount, and the -S magnet for CS1-B/DS1-B switches. When sizing, the 63 mm bore yields 1559 N push at 0.5 MPa; dropping to a 50 mm bore gives 982 N, while an 80 mm bore provides 2513 N. Because the 250 mm stroke is under 300 mm, rod bending is minimal, but for side loads use a guide. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X250SFTC
- ✓ 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 SI63X250SFTC FAQ
Yes, the SI63X250SFTC is discontinued. The direct replacement is the SAI63X250SFTC. It shares the same ISO 15552 mounting interface, 63 mm bore, 250 mm stroke, G3/8 port, and FTC trunnion, fitting existing fixtures perfectly while upgrading the piston seal.
The 63 mm bore uses a G3/8 port. At 0.5 MPa it provides 1559 N push and 1402 N pull force. At 0.7 MPa push is 2182 N, and at 0.9 MPa it is 2805 N. The theoretical maximum force is 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X250SFTC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X250SFTC replacement — usually within 7-8 hours.