This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X210SFB, 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 SI50X210SFB
The AirTAC Airtac SI50 Standard Cylinder SI50X210SFB 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 SAI50X210SFB, 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 → SAI50X210SFB
- 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 SI50X210SFB
The AirTAC SI50X210SFB is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 210mm stroke, and FB flange mounting. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50X210SFB, matching the interface, bore, stroke, force, and port.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also adds SAIL, SAIF, and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X210SFB Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X210SFB |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X210SFB |
| 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 SAI50X210SFB 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 SAI50X210SFB 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 SI50X210SFB
| 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 SI50X210SFB Is Used
Clamping Fixtures
Holds workpieces securely in machining jigs using the FB flange mount, delivering 982 N of clamping force at 0.5 MPa.
Package Diverting
Actuates routing gates on packaging lines, where the 210mm stroke provides ample travel to redirect boxes efficiently.
Replacing the Airtac SI50 Standard Cylinder SI50X210SFB with the SAI50X210SFB
To replace the SI50X210SFB, order the SAI50X210SFB. Verify the ISO 15552 mounting interface, 50mm bore, 210mm stroke, G1/4 port, FB flange, and the -S magnet. If you need more force, the 63mm bore yields 1559 N push at 0.5 MPa; if less is acceptable, the 40mm bore gives 628 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use a pilot check valve or SAIL/BSAI lock for load holding. At 210mm stroke, guide external rods to prevent side-loading and rod bending.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X210SFB
- ✓ 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 SI50X210SFB FAQ
Yes, the SI50X210SFB is discontinued. The direct replacement is the SAI50X210SFB. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 210mm stroke, FB flange, G1/4 port, and 982 N output force.
This 50mm bore cylinder uses a G1/4 air port. At 0.5 MPa it provides 982 N push and 825 N pull force. At 0.7 MPa push is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X210SFB
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X210SFB replacement — usually within 7-8 hours.