This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX350, 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 SI50AX350
The AirTAC Airtac SI50 Standard Cylinder SI50AX350 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 SAI50AX350, 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 → SAI50AX350
- 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 SI50AX350
The AirTAC SI50AX350 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 SAI50AX350, a direct upgrade retaining the exact mounting interface, bore, stroke, and force. The SAI features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and long life. This specific SKU uses an SUS420J2 stainless steel rod (-A) for corrosion resistance, but lacks a magnet, so it cannot accept a position switch.
The SAI family also introduces variants the SI line lacked, including the SAIL air-released lock, SAIF built-in valve, and BSAI clamp-lock. Note that a plain cylinder drifts on air loss; the adjustable 30mm cushions only decelerate near stroke ends. For high-heat environments, a Viton H seal option extends the operating range from -20...+70C up to 0-150C.
Airtac SI50 Standard Cylinder SI50AX350 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX350 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX350 |
| 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 SAI50AX350 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 SAI50AX350 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 SI50AX350
| 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 SI50AX350 Is Used
Diverting Mechanisms
Drives routing gates on packaging lines using the 982N push force, with the 350mm stroke providing full actuation reach.
Light Pressing Tasks
Applies downward clamping pressure for component seating, where the SUS420J2 stainless rod resists moisture.
Material Handling Lifts
Raises light pallets or totes vertically, safely handling loads near the 50kg vertical lift limit with external guides.
Replacing the Airtac SI50 Standard Cylinder SI50AX350 with the SAI50AX350
To replace the discontinued SI50AX350, order the SAI50AX350. Verify your ISO 15552 mounting fixture, the G1/4 air port, and the M16x1.5 rod thread. Because this SKU lacks the -S magnet, it cannot support CS1-B/DS1-B sensors; if sensing is needed, specify an SAI50X350S instead. When sizing, the 50mm bore yields 982N push and 825N pull at 0.5MPa. If you need less force, a 40mm bore provides 628N push; for more, a 63mm bore offers 1559N push. For the 350mm stroke, use external guides to prevent rod bending and side-load damage. A standard cylinder does not hold load without live air; for drop prevention, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX350
- ✓ 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 SI50AX350 FAQ
Yes, the AirTAC SI50AX350 is discontinued. The direct replacement is the SAI50AX350. It is dimensionally interchangeable per ISO 15552, keeping the same 50mm bore, 350mm stroke, 982N force, G1/4 port, and mounting interface.
The 50mm bore uses a G1/4 port. It generates 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200kgf at 1.0MPa. The piston rod is 20mm with an M16x1.5 thread.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX350
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX350 replacement — usually within 7-8 hours.