This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X210S, 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 SI50X210S
The AirTAC Airtac SI50 Standard Cylinder SI50X210S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 210mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X210S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke210 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X210S
- 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 SI50X210S
The AirTAC SI50X210S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 210mm stroke, delivering 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X210S, a direct sharing the exact interface, bore, stroke, force and mounting.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The -S suffix means a built-in piston magnet for legacy CS1-B/DS1-B sensors; the SAI uses current AirTAC switches. You can also spec Viton H seals for 0-150 C heat, or SAIL/BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50X210S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X210S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X210S |
| Bore size | Ø50 mm |
| Stroke | 210 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 SAI50X210S 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 SAI50X210S 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 SI50X210S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×210 | 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 SI50X210S Is Used
Package Diverting
Drives diverting arms on packaging lines using the 982 N push force and 210 mm stroke to redirect cartons at high speed.
Pallet Stopper Gate
Acts as a pneumatic stop gate for pallets, where the 50 kg vertical lift margin safely manages gate weight and friction.
Clamp Actuation
Secures medium workpieces during machining, relying on adjustable 30 mm cushions to soften end-of-stroke impacts.
Replacing the Airtac SI50 Standard Cylinder SI50X210S with the SAI50X210S
To replace the SI50X210S, order the SAI50X210S: it drops into the same ISO 15552 fixtures with identical 50mm bore, 210mm stroke, M16x1.5 rod thread, G1/4 port and 30mm cushions. Confirm your mounting accessory (LB, FA, TC, etc.) and thread standard (PT, G, NPT). The -S magnet is retained. If sizing up or down, neighbouring bores are 40mm (628 N push @0.5) and 63mm (1559 N push @0.5). Because stroke is 210mm, ensure adequate guiding to prevent rod bending under side loads. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external pilot check valve, rod lock, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X210S
- ✓ 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 SI50X210S FAQ
Yes, the SI50X210S is discontinued. The direct replacement is the SAI50X210S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 210mm stroke, G1/4 port, and mounting interface.
It features 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, 1767 N push at 0.9 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X210S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X210S replacement — usually within 7-8 hours.