This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X520S, 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 SI50X520S
The AirTAC Airtac SI50 Standard Cylinder SI50X520S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 520mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X520S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke520 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X520S
- 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 SI50X520S
The AirTAC SI50X520S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore and 520mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X520S, a direct upgrade retaining the exact interface, bore, stroke, and mounting hardware.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. It also introduces SAIL, SAIF, and BSAI lock variants absent in the SI line. The built-in magnet supports CS1-B/DS1-B switches, and seal options include high-temp Viton H.
Airtac SI50 Standard Cylinder SI50X520S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X520S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X520S |
| Bore size | Ø50 mm |
| Stroke | 520 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 SAI50X520S 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 SAI50X520S 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 SI50X520S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×520 | 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 SI50X520S Is Used
Long-Stroke Diversion
Pushes packages across transfer lanes with 982 N force, utilizing the 520mm stroke to bridge wide conveyor gaps smoothly.
Multi-Stage Ejection
Ejects machined parts from deep fixtures, relying on the 30mm adjustable air cushions to decelerate the rod at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X520S with the SAI50X520S
To replace the SI50X520S, order the SAI50X520S ensuring the ISO 15552 mounting interface, 50mm bore, 520mm stroke, G1/4 port, and M16x1.5 rod thread match your existing fixture. Retain your original mounting accessory (LB, FA, TC, etc.) and confirm the -S magnet for current AirTAC switch compatibility. Sizing both ways: a 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore yields 1559 N. Note that a plain cylinder drifts on air loss since the cushion only decelerates; for load holding, specify the SAIL lock variant or an external pilot check valve. Because the 520mm stroke is long, use external guides to prevent rod bending and side-load wear.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X520S
- ✓ 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 SI50X520S FAQ
Yes, the SI50X520S is discontinued. The direct replacement is the SAI50X520S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 520mm stroke, G1/4 port, and mounting interface, so it drops directly into existing fixtures.
The G1/4 port is fixed by the 50mm bore. 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 SAI50X520S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X520S replacement — usually within 7-8 hours.