This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63AX425S, 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 SI63AX425S
The AirTAC Airtac SI63 Standard Cylinder SI63AX425S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 425mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63AX425S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke425 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63AX425S
- 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 SI63AX425S
The AirTAC SI63AX425S is a discontinued double-acting ISO 15552 profile cylinder with a 63mm bore and 425mm stroke. It delivers 1559N push and 1402N pull at 0.5MPa, using a G3/8 port and an M16x1.5 SUS420J2 stainless steel rod. AirTAC replaced this legacy unit with the SAI63AX425S, a direct sharing the exact interface, force, and mounting. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life.
The built-in magnet supports legacy CS1-B/DS1-B sensors, while a plain cylinder needs live air; use a SAIL lock or external pilot check valve to hold loads. The Viton H seal option raises the -20 to +70C range to 150C.
Airtac SI63 Standard Cylinder SI63AX425S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63AX425S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63AX425S |
| Bore size | Ø63 mm |
| Stroke | 425 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 SAI63AX425S 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 SAI63AX425S 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 SI63AX425S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×425 | 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 SI63AX425S Is Used
Diverting Gates
Actuates heavy lane diverters on packaging lines, utilizing the 1559N force to push loaded pallets reliably at 0.5MPa.
Material Press
Provides consistent downward clamping pressure for assembly fixtures, with the 425mm stroke accommodating varying part heights.
Vertical Lifts
Raises components up to 79kg in storage buffers, requiring external guides to manage rod bending over the long 425mm extension.
Replacing the Airtac SI63 Standard Cylinder SI63AX425S with the SAI63AX425S
To replace the SI63AX425S, order the SAI63AX425S. Verify the ISO 15552 mounting interface, 63mm bore, 425mm stroke, G3/8 port, and the -S magnet for CS1-B/DS1-B switches. The -A suffix denotes the SUS420J2 stainless rod. Because this is a 425mm stroke, add external guides to prevent rod bending and side-load wear. If sizing down, a 50mm bore yields 982N push at 0.5MPa; sizing up to 80mm provides 2513N. Remember the cushion only decelerates; for load holding on air loss, select the SAIL or BSAI lock variant, or use a pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63AX425S
- ✓ 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 SI63AX425S FAQ
Yes, the SI63AX425S is discontinued. The direct replacement is the SAI63AX425S. It is dimensionally interchangeable per ISO 15552, retaining the same 63mm bore, 425mm stroke, output force, G3/8 port, and mounting interface.
At 0.5MPa it pushes 1559N and pulls 1402N. At 0.7MPa push is 2182N, and at 0.9MPa it is 2805N. The theoretical max is 318kgf at 1.0MPa, with an operating speed of 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63AX425S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63AX425S replacement — usually within 7-8 hours.