This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX650S, 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 SI50 Standard Cylinder SI50AX650S
The AirTAC Airtac SI50 Standard Cylinder SI50AX650S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 650mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX650S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke650 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX650S
- 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 SI50 Standard Cylinder SI50AX650S
The AirTAC SI50AX650S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 650 mm stroke. Delivering 982 N push force at 0.5 MPa, it features a SUS420J2 stainless piston rod, a G1/4 port, and a built-in magnet for CS1-B/DS1-B sensors. AirTAC replaced this legacy unit with the SAI50AX650S, a direct sharing the same interface, force, and mounting.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants absent from the SI line.
Airtac SI50 Standard Cylinder SI50AX650S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX650S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX650S |
| Bore size | Ø50 mm |
| Stroke | 650 mm |
| Acting type | Double acting |
| Port size | G1/4 |
| 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 1200 mm |
Specifications follow the official AirTAC SI datasheet (now discontinued). The SAI50AX650S carries the same ISO 15552 ratings. Confirm against the product label before installation. Thread options: PT / G / NPT.
Theoretical Output Force (Ø50mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 982 N | 825 N |
| 0.7 MPa | 1374 N | — |
| Max (@1.0 MPa) | 200 kgf | |
The SAI50AX650S produces the same force from the same bore. Actual usable force is lower than theoretical; size with a margin.
Model Code: Airtac SI50 Standard Cylinder SI50AX650S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×650 | 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 SI50 Standard Cylinder SI50AX650S Is Used
Long-Stroke Diversion
Pushes packages across a 650 mm transfer lane using the 982 N thrust class, guided externally to prevent rod bending.
Stainless Rod Actuation
Drives a moist-environment test fixture using the SUS420J2 rod option, switching seamlessly to the SAI direct.
Replacing the Airtac SI50 Standard Cylinder SI50AX650S with the SAI50AX650S
To replace the SI50AX650S, order the SAI50AX650S. It is dimensionally interchangeable per ISO 15552, preserving the 50 mm bore, 650 mm stroke, G1/4 port, M16x1.5 thread, and 30 mm cushions. Retain your existing mounting accessory and confirm the -S magnet for current AirTAC switches. If you need more force, the 63 mm bore offers 1559 N at 0.5 MPa; if less, the 40 mm bore provides 628 N. Because the 650 mm stroke invites rod bending, use an external guide to prevent side loads. A plain cylinder drifts on air loss, so for load holding choose the SAIL lock, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX650S
- ✓ Same bore / stroke / force
- ✓ Port/thread type (PT/G/NPT)
- ✓ Magnet (-S) for sensors?
- ✓ Mounting reused (FA/FB/CA/CB/CR/LB/TC)
Airtac SI50 Standard Cylinder SI50AX650S FAQ
Yes, the SI50AX650S is discontinued. The direct replacement is the SAI50AX650S. It shares the identical ISO 15552 mounting interface, 50 mm bore, 650 mm stroke, force, and G1/4 port, fitting existing fixtures perfectly.
The G1/4 port bore delivers a push of 982 N and pull of 825 N at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Operating pressure is 0.15-1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX650S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX650S replacement — usually within 7-8 hours.