This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X350SFA, 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 SI50X350SFA
The AirTAC Airtac SI50 Standard Cylinder SI50X350SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 350mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X350SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke350 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X350SFA
- 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 SI50X350SFA
The AirTAC SI50X350SFA is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 350mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X350SFA, a direct upgrade retaining the exact FA flange mount, M16x1.5 rod thread, and 30mm cushions.
The SAI replacement features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. The SAI family also adds SAIL lock, SAIF valve, and BSAI clamp variants the SI lacked.
Airtac SI50 Standard Cylinder SI50X350SFA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X350SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X350SFA |
| Bore size | Ø50 mm |
| Stroke | 350 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 SAI50X350SFA 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 SAI50X350SFA 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 SI50X350SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×350 | 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 SI50X350SFA Is Used
Package Diversion
Drives 50kg routing gates on packaging lines, utilizing the 350mm stroke to clear standard conveyor widths safely.
Vertical Pressing
Applies up to 982N of downward clamping force at 0.5MPa for light assembly presses and component seating tasks.
Pallet Stops
Extends 350mm to act as a high-cycle physical stop for pallets entering a wrapping or labeling station.
Replacing the Airtac SI50 Standard Cylinder SI50X350SFA with the SAI50X350SFA
To replace the SI50X350SFA, order the SAI50X350SFA. It drops into existing fixtures via the identical ISO 15552 mounting interface, matching the 50mm bore, 350mm stroke, G1/4 port, and FA flange. Retain the -S magnet for CS1-B/DS1-B legacy sensors (the SAI uses current AirTAC switches). For sizing, this bore yields 982N push at 0.5MPa; dropping to a 40mm bore gives 628N, while a 63mm bore provides 1559N. Because stroke is 350mm, use an external guide to prevent rod bending and side loads. A plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X350SFA
- ✓ 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 SI50X350SFA FAQ
Yes, the SI50X350SFA is discontinued. The direct replacement is the SAI50X350SFA. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 350mm stroke, G1/4 port, and FA flange mount.
The 50mm bore features a G1/4 air port and delivers 982N push / 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical maximum of 200kgf at 1.0MPa. It operates at 30-800mm/s with a 30mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X350SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X350SFA replacement — usually within 7-8 hours.