This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX85S, 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 SI50AX85S
The AirTAC SI50 Standard Cylinder SI50AX85S 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 SAI50AX85S, 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 → SAI50AX85S
- 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 SI50AX85S
The AirTAC SI50AX85S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 85mm stroke. It delivers 982N push and 825N pull at 0.5MPa through a G1/4 port. The direct replacement is the SAI50AX85S, which shares the same interface, force, and mounting fixtures.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This model includes a SUS420J2 stainless rod (-A) and a magnet (-S) for CS1-B/DS1-B switches.
Airtac SI50 Standard Cylinder SI50AX85S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX85S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX85S |
| 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 SAI50AX85S 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 SAI50AX85S 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 SI50AX85S
| 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 SI50AX85S Is Used
Stainless Rod Clamping
Ideal for mid-force clamping tasks where the SUS420J2 stainless piston rod resists moisture and corrosion better than standard carbon steel.
Package Diverting
Provides reliable 85mm stroke actuation to push or divert medium-weight packages along material handling lines using 982N of thrust.
Replacing the Airtac SI50 Standard Cylinder SI50AX85S with the SAI50AX85S
To replace the SI50AX85S, order the SAI50AX85S. Verify the ISO 15552 mounting interface, 85mm stroke, G1/4 port, and the -S magnet for legacy CS1-B/DS1-B sensors (the SAI uses current AirTAC switches). The -A rod denotes SUS420J2 stainless steel. If you need more force, the 63mm bore yields 1559N push at 0.5MPa; if less is needed, the 40mm bore yields 628N. For load holding on air loss, note that a plain cylinder drifts and the air cushion only decelerates. Use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX85S
- ✓ 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 SI50AX85S FAQ
Yes, the SI50AX85S is discontinued. The direct replacement is the SAI50AX85S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 85mm stroke, G1/4 port, and mounting interface, but adds an upgraded Y-shaped piston seal.
The bore is 50mm with a G1/4 air port. The thrust is 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa. The piston rod is 20mm with an M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX85S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX85S replacement — usually within 7-8 hours.