This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X645S, 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 SI63X645S
The AirTAC Airtac SI63 Standard Cylinder SI63X645S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 645mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63X645S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke645 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63X645S
- 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 SI63X645S
The AirTAC SI63X645S is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 645mm stroke. It delivers 1559N push and 1402N pull at 0.5MPa via a G3/8 port. AirTAC replaced this legacy unit with the SAI63X645S, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, force, port and accessories.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI63 Standard Cylinder SI63X645S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X645S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X645S |
| Bore size | Ø63 mm |
| Stroke | 645 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 SAI63X645S 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 SAI63X645S 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 SI63X645S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×645 | 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 SI63X645S Is Used
Long-Stroke Diversion
Drives large packages across transfer lines using the full 645mm travel, relying on external guides to absorb side loads during lateral pushing.
Fixture Actuation
Positions machining fixtures over wide spans, utilizing the 1559N thrust at 0.5MPa to clamp and locate heavy workpieces securely.
Replacing the Airtac SI63 Standard Cylinder SI63X645S with the SAI63X645S
To replace the SI63X645S, order the SAI63X645S. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G3/8 port, and the -S magnet for CS1-B/DS1-B switches. For sizing, a 63mm bore yields 1559N push at 0.5MPa; dropping to a 50mm bore gives 982N, while an 80mm bore provides 2513N. Because this is a 645mm stroke, use external guides to prevent rod bending and side-load damage. A plain cylinder drifts without air; for load holding on air loss, specify the SAIL or BSAI lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X645S
- ✓ 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 SI63X645S FAQ
Yes, the SI63X645S is discontinued. The direct replacement is the AirTAC SAI63X645S. It shares the identical ISO 15552 mounting interface, 63mm bore, 645mm stroke, output force, and G3/8 port, fitting your existing fixtures perfectly.
This double-acting cylinder features a G3/8 air port and M16x1.5 rod thread. It delivers 1559N push and 1402N pull at 0.5MPa, 2182N push at 0.7MPa, 2805N push at 0.9MPa, and a theoretical maximum force of 318kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63X645S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X645S replacement — usually within 7-8 hours.