This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX850S, 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 SI50BX850S
The AirTAC Airtac SI50 Standard Cylinder SI50BX850S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 850mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX850S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke850 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX850S
- 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 SI50BX850S
The AirTAC SI50BX850S is a discontinued double-acting ISO 15552 profile cylinder with an extruded aluminum barrel, delivering 982 N push force at 0.5 MPa. This 50 mm bore, 850 mm stroke variant features a SUS304 stainless piston rod (-B) and a built-in magnet (-S) for legacy CS1-B/DS1-B sensors. The direct replacement is the SAI50BX850S, retaining the same G1/4 port, M16x1.5 thread, and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and extended life. Note that plain cylinders drift without live air; for load holding, explore the SAIL or BSAI lock variants, or use an external pilot check valve.
Airtac SI50 Standard Cylinder SI50BX850S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX850S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX850S |
| Bore size | Ø50 mm |
| Stroke | 850 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 SAI50BX850S 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 SAI50BX850S 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 SI50BX850S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×850 | 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 SI50BX850S Is Used
Long-Stroke Diversion
Drives large package pushers across wide conveyor belts over the 850 mm travel.
Vertical Material Lift
Elevates 50 kg tote bins between warehouse levels using the 982 N thrust at 0.5 MPa.
Stainless Rod Washdown
Actuates washdown gating using the SUS304 rod option in food processing facilities.
Replacing the Airtac SI50 Standard Cylinder SI50BX850S with the SAI50BX850S
To replace the discontinued SI50BX850S, order the SAI50BX850S. Confirm the ISO 15552 mounting interface, 50 mm bore, 850 mm stroke, G1/4 port (PT/G/NPT thread options), and mounting accessory match your fixture. The -S magnet enables current AirTAC switches, while the -B rod provides SUS304 corrosion resistance. Sizing both ways: a 63 mm bore offers 1559 N push at 0.5 MPa, while a 40 mm bore yields 628 N. At 850 mm, prevent rod bending by using an external guide to absorb side loads. Because the air cushion only decelerates, use an external rod lock or pilot check valve for load holding.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX850S
- ✓ 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 SI50BX850S FAQ
Yes, the SI50BX850S is discontinued. The direct replacement is the SAI50BX850S. It is dimensionally interchangeable per ISO 15552, matching the 50 mm bore, 850 mm stroke, 982 N force, G1/4 port, and mounting interface.
The 50 mm bore features a G1/4 port. Force output is 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. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX850S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX850S replacement — usually within 7-8 hours.