This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X512S, 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 SI50X512S
The AirTAC Airtac SI50 Standard Cylinder SI50X512S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 512mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X512S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke512 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X512S
- 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 SI50X512S
The AirTAC SI50X512S is a discontinued double-acting ISO 15552 profile cylinder with a 50 mm bore and 512 mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X512S, a direct upgrade sharing the exact same mounting interface, bore, stroke, and output force.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The original SI-S model includes a piston magnet for CS1-B/DS1-B sensors, while the SAI replacement family also introduces SAIL, SAIF, and BSAI lock or valve variants the SI line lacked.
Airtac SI50 Standard Cylinder SI50X512S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X512S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X512S |
| Bore size | Ø50 mm |
| Stroke | 512 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 SAI50X512S 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 SAI50X512S 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 SI50X512S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×512 | 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 SI50X512S Is Used
Long-Stroke Diversion
The 512 mm stroke provides the extended reach needed to push heavy pallets or product lanes across wide conveyor belts.
Guided Carton Pusher
Drives carton sorting gates where the 982 N push force at 0.5 MPa is sufficient, provided external guides support the long rod.
Replacing the Airtac SI50 Standard Cylinder SI50X512S with the SAI50X512S
To replace the SI50X512S, order the SAI50X512S and confirm the ISO 15552 mounting interface, 50 mm bore, 512 mm stroke, G1/4 port (PT/G/NPT), and mounting accessory match your fixture. Because this is a 512 mm stroke, add external guides to prevent rod bending and side-load wear. If sizing up or down, neighboring bores are 40 mm and 63 mm; at 0.5 MPa the 40 mm yields 628 N push and the 63 mm yields 1559 N. A plain cylinder drifts on air loss—the cushion only decelerates—so for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. The -S suffix means a magnet is present for CS1-B/DS1-B switches.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X512S
- ✓ 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 SI50X512S FAQ
Yes, the AirTAC SI50X512S is discontinued. The direct replacement is the SAI50X512S. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 512 mm stroke, output force, G1/4 port, and mounting interface.
This double-acting cylinder has a G1/4 air port. The 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, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X512S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X512S replacement — usually within 7-8 hours.