This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX900S, 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 SI50AX900S
The AirTAC Airtac SI50 Standard Cylinder SI50AX900S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 900mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX900S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke900 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX900S
- 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 SI50AX900S
The AirTAC SI50AX900S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50 mm bore, 900 mm stroke, and a SUS420J2 stainless steel rod. It delivers 982 N push force at 0.5 MPa. AirTAC replaced this unit with the SAI50AX900S, a direct sharing the same interface, G1/4 port, and 200 kgf maximum force.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The original -S magnet supports CS1-B/DS1-B sensors, while the SAI uses modern switches.
Airtac SI50 Standard Cylinder SI50AX900S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX900S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX900S |
| Bore size | Ø50 mm |
| Stroke | 900 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 SAI50AX900S 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 SAI50AX900S 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 SI50AX900S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×900 | 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 SI50AX900S Is Used
Long-Stroke Diversion
Pushes packages across a 900 mm conveyor lane using the 982 N push force at 0.5 MPa, requiring external guides to prevent rod bending.
Corrosive Testing Fixture
Utilizes the SUS420J2 stainless rod in a 900 mm stroke test chamber, tracking position with the CS1-B/DS1-B sensors.
Replacing the Airtac SI50 Standard Cylinder SI50AX900S with the SAI50AX900S
To replace the SI50AX900S, order the SAI50AX900S. Verify the ISO 15552 mounting interface, 900 mm stroke, G1/4 port, and M16x1.5 rod thread. Because this is a 900 mm stroke, prevent rod bending by adding external guides to manage side loads. For sizing, a 40 mm bore offers 628 N push at 0.5 MPa, while a 63 mm bore yields 1559 N. Note that a standard cylinder drifts without air; use a pilot check valve or the SAIL/BSAI lock variant to hold loads. The -S magnet enables position sensing.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX900S
- ✓ 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 SI50AX900S FAQ
Yes, the SI50AX900S is discontinued. The direct replacement is the SAI50AX900S. It shares the exact ISO 15552 mounting interface, 50 mm bore, 900 mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
It has a G1/4 air port. The force ratings are: 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX900S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX900S replacement — usually within 7-8 hours.