This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X35SFA, 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 SI50X35SFA
The AirTAC Airtac SI50 Standard Cylinder SI50X35SFA is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 35mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X35SFA, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke35 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X35SFA
- 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 SI50X35SFA
The AirTAC SI50X35SFA is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 35mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, it is directly replaced by the SAI50X35SFA. This direct upgrade shares the exact FA flange mounting, M16x1.5 rod thread, and output force.
The SAI successor features an upgraded piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For position sensing, this -S model uses legacy CS1-B/DS1-B switches.
Airtac SI50 Standard Cylinder SI50X35SFA Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X35SFA |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X35SFA |
| Bore size | Ø50 mm |
| Stroke | 35 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 SAI50X35SFA 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 SAI50X35SFA 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 SI50X35SFA
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×35 | 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 SI50X35SFA Is Used
Short-Stroke Clamping
Ideal for holding workpieces in machining fixtures where a 35mm stroke provides rapid, precise clamping at 982N force.
Package Diverting
Drives a diverter arm on a packaging line, using the FA flange to mount rigidly and push light goods at high speed.
Replacing the Airtac SI50 Standard Cylinder SI50X35SFA with the SAI50X35SFA
To replace the SI50X35SFA, order the SAI50X35SFA. Confirm the ISO 15552 interface, 50mm bore, 35mm stroke, G1/4 port, FA flange mount, and the -S magnet for CS1-B/DS1-B sensors. If you need more force, the 63mm bore yields 1559N push at 0.5MPa; if less is acceptable, the 40mm bore provides 628N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X35SFA
- ✓ 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 SI50X35SFA FAQ
Yes, the AirTAC SI50X35SFA is discontinued. The direct replacement is the SAI50X35SFA. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 35mm stroke, G1/4 port, FA flange, and 982N force.
The bore is 50mm with a G1/4 air port. Force outputs are: 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X35SFA
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X35SFA replacement — usually within 7-8 hours.