This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63X685, 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 SI63X685
The AirTAC Airtac SI63 Standard Cylinder SI63X685 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 685mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63X685, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke685 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63X685
- 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 SI63X685
The AirTAC SI63X685 is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore and 685 mm stroke, delivering 1559 N push force at 0.5 MPa via a G3/8 port. AirTAC replaced it with the SAI63X685, a direct sharing the exact ISO 15552 mounting interface, bore, stroke, output force, and port size. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This non-magnet SKU cannot take a sensor.
The SAI family also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. Note that a plain cylinder drifts without live air; the cushion only decelerates near stroke end.
Airtac SI63 Standard Cylinder SI63X685 Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63X685 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63X685 |
| Bore size | Ø63 mm |
| Stroke | 685 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 SAI63X685 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 SAI63X685 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 SI63X685
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×685 | 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 SI63X685 Is Used
Press Ejection
Ejects formed parts from a press bed, relying on the 30 mm adjustable air cushions to decelerate the 63 mm bore at high speeds.
Replacing the Airtac SI63 Standard Cylinder SI63X685 with the SAI63X685
To replace the SI63X685, order the SAI63X685. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G3/8 port, and the M16x1.5 rod thread. Because this is a non-S SKU, it cannot accept a CS1-B or DS1-B sensor. If you need position sensing, select an SAI model with a magnet. For sizing alternatives, a 50 mm bore yields 982 N push at 0.5 MPa, while an 80 mm bore yields 2513 N. With a 685 mm stroke, use external guides to prevent rod bending and side-load damage. To hold a load securely on air loss, use an external rod lock, a pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63X685
- ✓ 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 SI63X685 FAQ
Yes, the SI63X685 is discontinued. The direct replacement is the AirTAC SAI63X685. It shares the same ISO 15552 mounting interface, 63 mm bore, 685 mm stroke, output force, and G3/8 port, fitting existing fixtures perfectly.
The 63 mm bore uses a G3/8 port. It delivers 1559 N push and 1402 N pull at 0.5 MPa, 2182 N push at 0.7 MPa, 2805 N at 0.9 MPa, and a theoretical max of 318 kgf at 1.0 MPa.
Request a Quote for the SAI63X685
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63X685 replacement — usually within 7-8 hours.