This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X403S, 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 SI50X403S
The AirTAC Airtac SI50 Standard Cylinder SI50X403S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 403mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X403S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke403 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X403S
- 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 SI50X403S
The AirTAC SI50X403S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 403mm stroke. It delivers 982N push and 825N pull at 0.5MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X403S, a direct sharing the exact ISO 15552 mounting interface, stroke, force, and accessories.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. The SAI family adds SAIL lock, SAIF valve, and BSAI clamp variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X403S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X403S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X403S |
| Bore size | Ø50 mm |
| Stroke | 403 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 SAI50X403S 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 SAI50X403S 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 SI50X403S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×403 | 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 SI50X403S Is Used
Package Diverting
Pushes cartons at 30-800 mm/s on packaging lines where the 982N push force easily handles moderate loads over the 403mm travel.
Fixture Actuation
Clamps workpieces in CNC cells using the ISO 15552 mounting interface, relying on the 825N pull force to hold the tooling securely.
Replacing the Airtac SI50 Standard Cylinder SI50X403S with the SAI50X403S
To replace the SI50X403S, order the SAI50X403S. Confirm the ISO 15552 mounting interface (LB, FA, TC, etc.), the G1/4 port, and the M16x1.5 rod thread. The -S suffix means it has a piston magnet for CS1-B/DS1-B switches; the SAI uses current AirTAC switches. If you need more force, the 63mm bore yields 1559N push at 0.5MPa; if less force is acceptable, the 40mm bore yields 628N. Note: a 403mm stroke invites rod bending; use external guides to prevent side-load damage. A plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use the SAIL lock, BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X403S
- ✓ 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 SI50X403S FAQ
Yes, the SI50X403S is discontinued. The direct replacement is the SAI50X403S. It shares the exact ISO 15552 mounting interface, 50mm bore, 403mm stroke, output force, G1/4 port, and mounting accessories, so it drops directly into existing fixtures.
It is a double-acting cylinder with a 20mm rod, M16x1.5 thread, 30mm cushion, and G1/4 port. Speed is 30-800 mm/s. Force ratings are 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200 kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X403S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X403S replacement — usually within 7-8 hours.