This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX85S, 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 SI50BX85S
The AirTAC Airtac SI50 Standard Cylinder SI50BX85S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 85mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX85S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke85 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX85S
- 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 SI50BX85S
The AirTAC SI50BX85S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 85mm stroke, G1/4 port, and a SUS304 stainless piston rod (-B) for corrosion resistance. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50BX85S. This direct upgrade shares identical ISO 15552 mounting dimensions, output force, and accessories.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. It retains the built-in magnet (-S) for legacy CS1-B/DS1-B sensors. Note that air cushions only decelerate; for load holding, explore the SAIL or BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX85S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX85S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX85S |
| Bore size | Ø50 mm |
| Stroke | 85 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 SAI50BX85S 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 SAI50BX85S 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 SI50BX85S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×85 | 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 SI50BX85S Is Used
Stainless Rod Clamping
Ideal for packaging machinery requiring corrosion resistance, using the SUS304 rod to clamp components with 982 N of force at 0.5 MPa.
Mid-Stroke Diverting
The 85mm stroke provides precise actuation for diverting light to medium products along a handling line without overextending.
Replacing the Airtac SI50 Standard Cylinder SI50BX85S with the SAI50BX85S
To replace the SI50BX85S, order the SAI50BX85S to ensure the ISO 15552 mounting interface, 50mm bore, 85mm stroke, G1/4 port, and SUS304 rod are matched perfectly. When sizing, consider the neighbouring 40mm bore (628 N push @0.5 MPa) or 63mm bore (1559 N push @0.5 MPa) to scale force. If your application requires load holding on air loss, a standard cylinder drifts; use an external pilot check valve or the SAIL/BSAI lock variants. The -S magnet supports CS1-B/DS1-B switches, while the SAI family accommodates current AirTAC sensors. For high-temperature environments up to 150 C, select the Viton H seal option.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX85S
- ✓ 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 SI50BX85S FAQ
Yes, the AirTAC SI50BX85S is discontinued. The direct replacement is the SAI50BX85S. It shares the same ISO 15552 mounting interface, 50mm bore, 85mm stroke, G1/4 port, and force ratings, fitting existing fixtures perfectly.
The 50mm bore features a G1/4 air port. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX85S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX85S replacement — usually within 7-8 hours.