This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI63AX125S, 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 SI63AX125S
The AirTAC Airtac SI63 Standard Cylinder SI63AX125S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø63mm bore and 125mm stroke, G3/8 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI63AX125S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ63 mm
- Stroke125 mm
- Port sizeG3/8
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI63AX125S
- 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 SI63AX125S
The AirTAC SI63AX125S is a discontinued double-acting ISO 15552 profile cylinder with a 63 mm bore and 125 mm stroke. It delivers 1559 N push force at 0.5 MPa through a G3/8 port. The direct replacement is the SAI63AX125S, which matches the ISO 15552 mounting interface, stroke, force and porting exactly. The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. This unit features a SUS420J2 stainless rod and a piston magnet for CS1-B/DS1-B switches.
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 held loads use an external rod lock or pilot check valve.
Airtac SI63 Standard Cylinder SI63AX125S Technical Specifications
| Model | Airtac SI63 Standard Cylinder SI63AX125S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI63AX125S |
| Bore size | Ø63 mm |
| Stroke | 125 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 SAI63AX125S 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 SAI63AX125S 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 SI63AX125S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 63 | Bore size in mm. |
| ×125 | 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 SI63AX125S Is Used
Clamping Fixtures
Holds workpieces securely in machining stations using 1559 N of thrust at 0.5 MPa.
Package Diverting
Actuates routing gates on 63 mm bore assembly lines with a 125 mm stroke length.
Replacing the Airtac SI63 Standard Cylinder SI63AX125S with the SAI63AX125S
To replace the SI63AX125S, order the SAI63AX125S. Confirm the ISO 15552 mounting interface, 125 mm stroke, G3/8 port, M16x1.5 rod thread and the -S magnet for current AirTAC switches. If you need less force, the 50 mm bore yields 982 N push at 0.5 MPa; for more power, the 80 mm bore gives 2513 N. For this 125 mm stroke, standard mounts work well, but for any stroke over 300 mm add a guide to prevent rod bending. To hold a load without live air, use the SAIL or BSAI lock variant, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI63AX125S
- ✓ 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 SI63AX125S FAQ
Yes, the SI63AX125S is discontinued. The direct replacement is the SAI63AX125S. It is dimensionally interchangeable per ISO 15552, keeping the same 63 mm bore, 125 mm stroke, G3/8 port and mounting interface.
The 63 mm bore uses a G3/8 port. It generates 1559 N push and 1402 N pull at 0.5 MPa, 2182 N push at 0.7 MPa, and 2805 N push at 0.9 MPa. The theoretical maximum force is 318 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI63AX125S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI63AX125S replacement — usually within 7-8 hours.