This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X35S, 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 SI50X35S
The AirTAC Airtac SI50 Standard Cylinder SI50X35S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X35S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X35S
- 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 SI50X35S
The AirTAC SI50X35S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 35mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this with the SAI50X35S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S suffix indicates a piston magnet for legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X35S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X35S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X35S |
| Bore size | Ø50 mm |
| Stroke | 35 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 SAI50X35S 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 SAI50X35S 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 SI50X35S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×35 | 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 SI50X35S Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with its 35mm stroke and 982N push force at 0.5MPa.
Package Diverting
Provides rapid actuation for sorting light to medium packages on a production line at 30-800mm/s.
Pallet Stopper
Acts as a reliable pneumatic stop mechanism for pallets entering a workstation, handling 50kg vertical loads.
Replacing the Airtac SI50 Standard Cylinder SI50X35S with the SAI50X35S
To replace the SI50X35S, order the SAI50X35S. It drops into existing fixtures using the same ISO 15552 mounting interface, 50mm bore, 35mm stroke, G1/4 port, and M16x1.5 rod thread. Retain your mounting accessory (LB, FA, TC, etc.) and confirm the -S magnet for current AirTAC switches. If sizing up, a 63mm bore yields 1559N at 0.5MPa; sizing down to 40mm gives 628N. Remember, a plain cylinder drifts on air loss as the cushion only decelerates. For load holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X35S
- ✓ 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 SI50X35S FAQ
Yes, the SI50X35S is discontinued. The direct replacement is the AirTAC SAI50X35S. It shares the identical ISO 15552 mounting interface, 50mm bore, 35mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
The 50mm bore features a G1/4 air port. Force output is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and 1767N push at 0.9MPa. The theoretical maximum force is 200kgf at 1.0MPa.
Request a Quote for the SAI50X35S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X35S replacement — usually within 7-8 hours.