This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX650, 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 SI50AX650
The AirTAC Airtac SI50 Standard Cylinder SI50AX650 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 SAI50AX650, 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 → SAI50AX650
- 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 SI50AX650
The AirTAC SI50AX650 is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 650 mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50AX650, a direct upgrade retaining the exact same mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. This SKU features a SUS420J2 stainless steel rod but lacks a magnet, meaning it cannot accept position sensors. For load holding, note that air cushions only decelerate; you need an external pilot check valve or the SAIL lock variant to prevent drift.
Airtac SI50 Standard Cylinder SI50AX650 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX650 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX650 |
| 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 SAI50AX650 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 SAI50AX650 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 SI50AX650
| 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 SI50AX650 Is Used
Long-Stroke Diversion
Pushes packages across a 650 mm conveyor lane using the 982 N push force at 0.5 MPa, requiring external guides to manage rod extension safely.
Stainless Rod Actuation
Drives moist or mildly corrosive clamping fixtures using the SUS420J2 stainless steel piston rod option for enhanced corrosion resistance.
Replacing the Airtac SI50 Standard Cylinder SI50AX650 with the SAI50AX650
To replace the SI50AX650, order the SAI50AX650. Verify your ISO 15552 mounting fixtures, the G1/4 air port, and the M16x1.5 rod thread. Because this 650 mm stroke exceeds 300 mm, add external guides to prevent rod bending and side-load damage. If you need more force, the 63 mm bore yields 1559 N push at 0.5 MPa; if less is required, the 40 mm bore provides 628 N. This non-magnetic SKU cannot support switches, unlike the -S variants using CS1-B/DS1-B sensors. For applications requiring load holding on air loss, select the SAIL or BSAI lock variant instead of relying on the adjustable cushion.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX650
- ✓ 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 SI50AX650 FAQ
Yes, the SI50AX650 is discontinued. The direct replacement is the SAI50AX650. It is dimensionally interchangeable per ISO 15552, keeping the same 50 mm bore, 650 mm stroke, 982 N force, and G1/4 port.
The bore is 50 mm with a G1/4 air port. At 0.5 MPa it pushes 982 N and pulls 825 N. At 0.7 MPa push is 1374 N, and the theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX650
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX650 replacement — usually within 7-8 hours.