This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX35S, 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 SI50BX35S
The AirTAC Airtac SI50 Standard Cylinder SI50BX35S 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 SAI50BX35S, 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 → SAI50BX35S
- 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 SI50BX35S
The AirTAC SI50BX35S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore, 35 mm stroke, and a SUS304 stainless steel rod. Generating 982 N push force at 0.5 MPa, it is replaced by the SAI50BX35S. This direct upgrade retains the G1/4 port, M16x1.5 thread, and mounting interface, but adds an upgraded two Y-shaped one-way piston seal for lower start-up pressure.
The SAI family introduces SAIL, SAIF, and BSAI lock variants absent in the legacy SI line. This -S SKU includes a piston magnet for CS1-B/DS1-B sensors, while the SAI uses current AirTAC switches.
Airtac SI50 Standard Cylinder SI50BX35S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX35S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX35S |
| 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 SAI50BX35S 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 SAI50BX35S 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 SI50BX35S
| 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 SI50BX35S Is Used
Stainless Rod Clamping
Ideal for short-stroke clamping in machining fixtures, utilizing the SUS304 rod for corrosion resistance in wet environments.
Package Diverting
Provides 982 N of push force at 0.5 MPa to actuate diverters on packaging lines, with a 35 mm stroke for rapid cycling.
Replacing the Airtac SI50 Standard Cylinder SI50BX35S with the SAI50BX35S
To replace the SI50BX35S, order the SAI50BX35S, confirming the ISO 15552 mounting interface, 50 mm bore, 35 mm stroke, G1/4 port, and magnet. The -B rod is SUS304 stainless steel; default is carbon steel. If you need more force, the 63 mm bore yields 1559 N push at 0.5 MPa; for less, the 40 mm bore gives 628 N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant to hold loads. With a 35 mm stroke, side-load risks are minimal, but ensure straight alignment.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX35S
- ✓ 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 SI50BX35S FAQ
Yes, the SI50BX35S is discontinued. The direct replacement is the SAI50BX35S, which shares the same ISO 15552 mounting interface, 50 mm bore, 35 mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
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, and a theoretical maximum of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX35S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX35S replacement — usually within 7-8 hours.