This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X620S, 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 SI50X620S
The AirTAC Airtac SI50 Standard Cylinder SI50X620S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 620mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X620S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke620 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X620S
- 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 SI50X620S
The AirTAC SI50X620S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore and 620mm stroke. It delivers 982 N push force at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X620S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, force, and port size.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The SAI family also introduces lock and valve variants the SI lacked, such as the SAIL and BSAI clamp-lock. This -S model includes a piston magnet for CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X620S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X620S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X620S |
| Bore size | Ø50 mm |
| Stroke | 620 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 SAI50X620S 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 SAI50X620S 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 SI50X620S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×620 | 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 SI50X620S Is Used
Long-Stroke Diversion
Pushes packages across a 620mm transfer belt using the 982 N push force at 0.5 MPa, guided externally to prevent rod bending.
Pneumatic Slide Table
Moves tooling trays 620mm between stations, relying on the adjustable 30mm air cushions to decelerate the 50mm bore at stroke ends.
Replacing the Airtac SI50 Standard Cylinder SI50X620S with the SAI50X620S
To replace the SI50X620S, order the SAI50X620S. Confirm the ISO 15552 mounting interface, the 620mm stroke, the G1/4 port (PT/G/NPT), and your mounting accessory (LB, FA, TC, etc.). The -S suffix means a magnet is present for CS1-B/DS1-B switches; a no-S SKU cannot take a sensor. Sizing both ways: the neighboring 63mm bore yields 1559 N push at 0.5 MPa, while the 40mm bore yields 628 N. For load holding, note a plain cylinder drifts on air loss—the cushion only decelerates—so use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. Because the 620mm stroke is long, prevent rod bending by using external guides to manage side loads.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X620S
- ✓ 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 SI50X620S FAQ
Yes, the SI50X620S is discontinued. The direct replacement is the SAI50X620S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 620mm stroke, 982 N force, G1/4 port, and mounting interface.
At 0.5 MPa, push force is 982 N and pull is 825 N. At 0.7 MPa push is 1374 N, and max theoretical force is 200 kgf at 1.0 MPa. It uses a G1/4 port, operates at 30-800 mm/s, and has a 20mm rod with M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X620S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X620S replacement — usually within 7-8 hours.