This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX350S, 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 SI50BX350S
The AirTAC Airtac SI50 Standard Cylinder SI50BX350S 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 SAI50BX350S, 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 → SAI50BX350S
- 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 SI50BX350S
The AirTAC SI50BX350S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 350mm stroke, and a SUS304 stainless steel rod. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the SAI50BX350S. This direct upgrade shares identical ISO 15552 mounting dimensions, bore, stroke, and output force.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The original -S magnet supports legacy CS1-B/DS1-B sensors, while the SAI family introduces SAIL, SAIF, and BSAI lock variants absent in the SI line.
Airtac SI50 Standard Cylinder SI50BX350S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX350S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX350S |
| 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 SAI50BX350S 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 SAI50BX350S 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 SI50BX350S
| 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 SI50BX350S Is Used
Stainless Rod Diverters
Ideal for pushing packages on packaging lines where the SUS304 rod resists moisture and corrosion over the 350mm travel.
Guided Vertical Lifts
Handles roughly 50kg loads in vertical material handling tasks, provided external guides absorb side-load forces.
Machine Tool Loading
Moves workpieces into machining centers using the 982N thrust, relying on adjustable cushions to decelerate at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50BX350S with the SAI50BX350S
To replace the SI50BX350S, order the SAI50BX350S. Verify the ISO 15552 mounting interface, 50mm bore, 350mm stroke, G1/4 port, and M16x1.5 rod thread. Because this uses a 350mm stroke, prevent rod bending by ensuring external guides handle side loads. Sizing options: a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore yields 1559N. Note that a plain cylinder drifts without air; the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant. The -B rod is SUS304 stainless, and the -S magnet works with legacy CS1-B/DS1-B switches.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX350S
- ✓ 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 SI50BX350S FAQ
Yes, the SI50BX350S is discontinued. The direct replacement is the SAI50BX350S. It is dimensionally interchangeable per ISO 15552, maintaining the same 50mm bore, 350mm stroke, 982N force, G1/4 port, and mounting interface.
The G1/4 port feeds a 50mm bore that generates 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200kgf at 1.0MPa. It operates at 30-800mm/s with a 30mm adjustable air cushion at each end.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX350S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX350S replacement — usually within 7-8 hours.