This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX350SFTC, 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 SI50BX350SFTC
The AirTAC Airtac SI50 Standard Cylinder SI50BX350SFTC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX350SFTC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX350SFTC
- 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 SI50BX350SFTC
The AirTAC SI50BX350SFTC is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 350mm stroke, and a SUS304 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it is directly replaced by the SAI50BX350SFTC. This direct successor shares the exact ISO 15552 mounting interface, G1/4 port, and FTC trunnion mount, fitting existing fixtures perfectly.
The SAI upgrade introduces a two Y-shaped one-way piston seal 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, while the -B rod resists corrosion.
Airtac SI50 Standard Cylinder SI50BX350SFTC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX350SFTC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX350SFTC |
| Bore size | Ø50 mm |
| Stroke | 350 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 SAI50BX350SFTC 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 SAI50BX350SFTC 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 SI50BX350SFTC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×350 | 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 SI50BX350SFTC Is Used
Stainless Rod Diverter
Ideal for pushing packages on a washdown conveyor line, utilizing the 350mm stroke and SUS304 rod for corrosion resistance.
Palletizing Gate
Actuates safety gates or light pallet stops where the 982 N thrust and 350mm travel distance are required.
Replacing the Airtac SI50 Standard Cylinder SI50BX350SFTC with the SAI50BX350SFTC
To replace the SI50BX350SFTC, order the SAI50BX350SFTC, confirming the ISO 15552 interface, 50mm bore, 350mm stroke, G1/4 port, and FTC trunnion mount. If downsizing, a 40mm bore yields 628 N push at 0.5 MPa; if upsizing, a 63mm bore provides 1559 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock or pilot check valve for load holding, or specify the SAIL/BSAI lock variant. The 350mm stroke requires an external guide to prevent rod bending under side loads. The -S magnet supports CS1-B/DS1-B switches, and the -B rod offers SUS304 stainless steel corrosion resistance.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX350SFTC
- ✓ 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 SI50BX350SFTC FAQ
Yes, the SI50BX350SFTC is discontinued. The direct replacement is the SAI50BX350SFTC. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 350mm stroke, G1/4 port, and FTC mounting interface.
It features a G1/4 air port and M16x1.5 rod thread. 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 SAI50BX350SFTC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX350SFTC replacement — usually within 7-8 hours.