This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63AX250S, 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 SI63AX250S
The AirTAC Airtac SI63 Standard Cylinder SI63AX250S 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 SAI63AX250S, 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 → SAI63AX250S
- 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 SI63AX250S
The AirTAC SI63AX250S is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore, 250 mm stroke, and a SUS420J2 stainless piston rod. Delivering 1559 N push and 1402 N pull at 0.5 MPa, it is replaced by the SAI63AX250S. This direct successor shares the exact G3/8 port, M16x1.5 thread, and ISO 15552 mounting interface, fitting existing fixtures seamlessly.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI63 Standard Cylinder SI63AX250S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63AX250S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63AX250S |
| 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 SAI63AX250S 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 SAI63AX250S 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 SI63AX250S
| 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 SI63AX250S Is Used
Stainless Rod Actuation
Drives mid-force tooling stages where the SUS420J2 rod resists moisture and corrosion better than standard carbon steel.
Package Diverting
Pushes cartons or totes at 30-800 mm/s using the 1559 N thrust class, fitting neatly into ISO 15552 fixture spacing.
Replacing the Airtac SI63 Standard Cylinder SI63AX250S with the SAI63AX250S
To replace the SI63AX250S, order the SAI63AX250S. Confirm the ISO 15552 mounting interface, 63 mm bore, 250 mm stroke, G3/8 port, and your specific mounting accessory. The SAI direct keeps the SUS420J2 stainless rod and -S magnet for current AirTAC switches. For sizing, neighboring bores are 50 mm (982 N push @0.5 MPa) and 80 mm (2513 N push @0.5 MPa). A plain cylinder drifts on air loss, as the 30 mm adjustable cushion only decelerates; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 250 mm stroke, ensure guide alignment to prevent rod bending side-loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63AX250S
- ✓ 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 SI63AX250S FAQ
Yes, the SI63AX250S is discontinued. The direct replacement is the SAI63AX250S. It is dimensionally interchangeable per ISO 15552, retaining the same 63 mm bore, 250 mm stroke, G3/8 port, and mounting interface.
The G3/8 port bore 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. It operates at 30-800 mm/s with a 30 mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63AX250S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63AX250S replacement — usually within 7-8 hours.