This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X540S, 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 SI50X540S
The AirTAC Airtac SI50 Standard Cylinder SI50X540S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 540mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X540S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke540 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X540S
- 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 SI50X540S
The AirTAC SI50X540S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 540 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X540S, a direct upgrade retaining the exact interface, bore, stroke, force and mounting.
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 CS1-B/DS1-B sensors, while the SAI family expands options with SAIL lock, SAIF valve and BSAI clamp variants.
Airtac SI50 Standard Cylinder SI50X540S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X540S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X540S |
| Bore size | Ø50 mm |
| Stroke | 540 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 SAI50X540S 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 SAI50X540S 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 SI50X540S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×540 | 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 SI50X540S Is Used
Long-Stroke Diversion
Pushes packages across a transfer line using the full 540 mm travel, relying on the 982 N thrust at 0.5 MPa to overcome friction.
Material Ejection
Ejects machined parts from a fixture, using adjustable end cushions to decelerate the 30-800 mm/s speed smoothly.
Replacing the Airtac SI50 Standard Cylinder SI50X540S with the SAI50X540S
To replace the SI50X540S, order the SAI50X540S. Confirm the ISO 15552 mounting interface (LB, FA, CA, TC, etc.), the G1/4 port, and the -S magnet for current AirTAC switches. Sizing checks: a 40 mm bore yields 628 N push at 0.5 MPa, while a 63 mm bore yields 1559 N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, specify the SAIL or BSAI lock variant, or use an external pilot check valve. Because the 540 mm stroke is long, use external guides to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X540S
- ✓ 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 SI50X540S FAQ
Yes, the SI50X540S is discontinued. The direct replacement is the SAI50X540S. It is dimensionally interchangeable per ISO 15552, matching the 50 mm bore, 540 mm stroke, G1/4 port, and mounting fixtures.
It features a G1/4 air port and M16x1.5 rod thread. Force output is 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, with a theoretical max of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X540S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X540S replacement — usually within 7-8 hours.