This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX850, 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 SI50BX850
The AirTAC Airtac SI50 Standard Cylinder SI50BX850 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 SAI50BX850, 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 → SAI50BX850
- 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 SI50BX850
The AirTAC SI50BX850 is a discontinued double-acting ISO 15552 profile cylinder with an extruded aluminum barrel, delivering 982 N push force at 0.5 MPa through its 50 mm bore and G1/4 port. This SKU features a SUS304 stainless steel piston rod for corrosion resistance but lacks a magnet, meaning it cannot accept position sensors.
AirTAC replaced this legacy unit with the SAI50BX850, a direct upgrade retaining the exact ISO 15552 mounting interface, 850 mm stroke, and force. The SAI uses an upgraded piston seal with two Y-shaped one-way elements for lower start-up pressure.
Airtac SI50 Standard Cylinder SI50BX850 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX850 |
| 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 SAI50BX850 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 SAI50BX850 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 SI50BX850
| 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 SI50BX850 Is Used
Long-Stroke Diversion
Actuates large diverter gates on packaging lines, utilizing the 850 mm stroke to clear wide product flows.
Corrosive Washdown
Drives tooling in parts washers where the SUS304 stainless rod resists moisture and chemicals.
Replacing the Airtac SI50 Standard Cylinder SI50BX850 with the SAI50BX850
To replace the SI50BX850, order the SAI50BX850 direct equivalent, verifying your ISO 15552 mounting hardware (LB, FA, TC, etc.), G1/4 port thread (PT/G/NPT), and the SUS304 rod option. Because this 850 mm stroke is long, add external guides to prevent rod bending and side-load damage. Sizing options: the 50 mm bore yields 982 N push at 0.5 MPa; step down to a 40 mm bore for 628 N, or up to a 63 mm bore for 1559 N. This non-magnetic SKU cannot take sensors; if you need position feedback, select an SAI model with the S suffix for CS1-B/DS1-B switches. Note that air cushions only decelerate the load; for load holding on air loss, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX850
- ✓ 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 SI50BX850 FAQ
Yes, the AirTAC SI50BX850 is discontinued. The direct replacement is the SAI50BX850. It is dimensionally interchangeable per the ISO 15552 mounting interface, matching the 50 mm bore, 850 mm stroke, force, and G1/4 port for a seamless fixture swap.
The 50 mm bore uses a G1/4 air port. 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 maximum of 200 kgf at 1.0 MPa. Operating speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX850 replacement — usually within 7-8 hours.