This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX210S, 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 SI50BX210S
The AirTAC Airtac SI50 Standard Cylinder SI50BX210S 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 SAI50BX210S, 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 → SAI50BX210S
- 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 SI50BX210S
The AirTAC SI50BX210S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 210mm stroke, and a SUS304 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50BX210S. This direct successor shares the same G1/4 port, M16x1.5 thread, and ISO 15552 mounting interface.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. The legacy CS1-B/DS1-B sensors fit the -S magnet here, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50BX210S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX210S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX210S |
| 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 SAI50BX210S 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 SAI50BX210S 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 SI50BX210S
| 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 SI50BX210S Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, using the SUS304 rod to clamp parts reliably with 982 N of push force at 0.5 MPa.
Diversion Gate Actuation
Provides robust 210mm stroke movement for routing products on stainless steel washdown conveyors where a standard carbon rod would degrade.
Replacing the Airtac SI50 Standard Cylinder SI50BX210S with the SAI50BX210S
To replace the SI50BX210S, order the SAI50BX210S, confirming the ISO 15552 interface, 50mm bore, 210mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. The -B rod denotes SUS304 stainless steel, ideal for corrosion resistance over the standard carbon steel. Sizing both ways: the 50mm bore yields 982 N push at 0.5 MPa (1374 N at 0.7 MPa); if less force is needed, a 40mm bore provides 628 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. At 210mm stroke, rod bending is low, but ensure guide alignment to prevent side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX210S
- ✓ 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 SI50BX210S FAQ
Yes, the AirTAC SI50BX210S is discontinued. The direct replacement is the SAI50BX210S. It shares the exact same ISO 15552 mounting interface, 50mm bore, 210mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The 50mm bore features a G1/4 air port and M16x1.5 rod thread. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and 1767 N push at 0.9 MPa, with a theoretical max force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX210S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX210S replacement — usually within 7-8 hours.