This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63AX550S, 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 SI63AX550S
The AirTAC Airtac SI63 Standard Cylinder SI63AX550S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 550mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63AX550S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke550 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63AX550S
- 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 SI63AX550S
The AirTAC SI63AX550S is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 550mm stroke. It delivers 1559N push force at 0.5MPa through a G3/8 port. The direct replacement is the SAI63AX550S, sharing the same interface, force, and mounting. The SAI features an upgraded piston seal with two Y-shaped elements for lower start-up pressure and longer life. This -A variant uses a SUS420J2 stainless rod for corrosion resistance, and the -S magnet works with legacy CS1-B/DS1-B sensors.
The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock or pilot check valve.
Airtac SI63 Standard Cylinder SI63AX550S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63AX550S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63AX550S |
| Bore size | Ø63 mm |
| Stroke | 550 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 SAI63AX550S 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 SAI63AX550S 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 SI63AX550S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×550 | 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 SI63AX550S Is Used
Material Lowering
Controls the descent of 79kg payloads using adjustable air cushions, requiring external guides to manage the long 550mm rod extension.
Stainless Rod Actuation
Drives tooling in humid washdown environments using the SUS420J2 stainless piston rod to resist corrosion over extended cycles.
Replacing the Airtac SI63 Standard Cylinder SI63AX550S with the SAI63AX550S
To replace the SI63AX550S, order the SAI63AX550S. Confirm the ISO 15552 mounting interface, 63mm bore, 550mm stroke, G3/8 port, and your specific mounting accessory (LB, FA, TC, etc.). The -A rod is SUS420J2 stainless, and the -S magnet enables position sensing. If you need less force, a 50mm bore gives 982N push at 0.5MPa; if you need more, an 80mm bore yields 2513N. Because 550mm exceeds 300mm, add external guides to prevent rod bending under side loads. A plain cylinder does not hold load without air; use a pilot check valve or the SAIL lock variant for secure holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63AX550S
- ✓ 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 SI63AX550S FAQ
Yes, the SI63AX550S is discontinued. The direct replacement is the SAI63AX550S. It is dimensionally interchangeable per ISO 15552, retaining the same 63mm bore, 550mm stroke, G3/8 port, and mounting interface. You simply order the SAI equivalent.
It features a G3/8 port, a 20mm rod, and an M16x1.5 thread. Force output is 1559N push and 1402N pull at 0.5MPa, 2182N push at 0.7MPa, 2805N push at 0.9MPa, and a theoretical maximum of 318kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63AX550S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63AX550S replacement — usually within 7-8 hours.