This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX350S, 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 SI50AX350S
The AirTAC Airtac SI50 Standard Cylinder SI50AX350S 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 SAI50AX350S, 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 → SAI50AX350S
- 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 SI50AX350S
The AirTAC SI50AX350S 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. The direct replacement is the SAI50AX350S, which matches the exact ISO 15552 mounting interface, stroke, force, and accessories.
The SAI upgrade features a new piston seal with two Y-shaped one-way elements for low start-up pressure. The -A suffix denotes a SUS420J2 stainless rod, and the -S magnet pairs with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50AX350S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX350S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX350S |
| 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 SAI50AX350S 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 SAI50AX350S 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 SI50AX350S
| 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 SI50AX350S Is Used
Package Diversion
Drives sorting arms on packaging lines where the 982N push force easily deflects standard cartons.
Stainless Rod Actuation
Actuates tooling in humid washdown areas using the SUS420J2 stainless piston rod to resist corrosion.
Replacing the Airtac SI50 Standard Cylinder SI50AX350S with the SAI50AX350S
To replace the SI50AX350S, order the SAI50AX350S. Verify the ISO 15552 mounting interface, 50mm bore, 350mm stroke, G1/4 port, and SUS420J2 stainless rod. At 0.5MPa it yields 982N push and 825N pull; sizing down to 40mm gives 628N, while sizing up to 63mm gives 1559N. For this 350mm stroke, use an external guide to prevent rod-bending side loads. The cushion only decelerates; for load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX350S
- ✓ 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 SI50AX350S FAQ
Yes, the SI50AX350S is discontinued. The direct replacement is the SAI50AX350S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 350mm stroke, G1/4 port, and mounting fixtures.
It features a G1/4 port and delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200kgf at 1.0MPa. The SAI replacement retains these exact ratings.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX350S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX350S replacement — usually within 7-8 hours.