This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX350STC, 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 SI50BX350STC
The AirTAC Airtac SI50 Standard Cylinder SI50BX350STC 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 SAI50BX350STC, 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 → SAI50BX350STC
- 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 SI50BX350STC
The AirTAC SI50BX350STC is a discontinued double-acting ISO 15552 profile cylinder featuring a SUS304 stainless steel rod, a 350mm stroke, and a TC trunnion mount. Delivering 982N push force at 0.5MPa, it is replaced by the SAI50BX350STC. This direct upgrade matches the bore, port G1/4, and ISO 15552 mounting dimensions.
The SAI successor introduces an upgraded two-piece Y-shaped piston seal for lower start-up pressure and longer life. The original -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI uses current switches.
Airtac SI50 Standard Cylinder SI50BX350STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX350STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX350STC |
| 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 SAI50BX350STC 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 SAI50BX350STC 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 SI50BX350STC
| 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 SI50BX350STC Is Used
Stainless Diverters
Ideal for food-grade or washdown conveyor routing where the SUS304 rod resists corrosion and the 982N force cleanly pushes packages.
Pallet Lift Gates
The TC trunnion mount handles pivotal articulation on 350mm stroke lift gates, moving loads safely within the 50kg vertical limit.
Film Roll Tensioning
Provides steady pulling force (825N at 0.5MPa) for packaging web handling, with adjustable cushions decelerating the 350mm travel.
Replacing the Airtac SI50 Standard Cylinder SI50BX350STC with the SAI50BX350STC
To replace the SI50BX350STC, order the SAI50BX350STC. Verify the ISO 15552 TC trunnion mounting, 50mm bore, 350mm stroke, G1/4 port, and the -S magnet. If downsizing, a 40mm bore yields 628N push; if upsizing, a 63mm bore provides 1559N. For the 350mm stroke, use an external guide to prevent rod bending and side-load wear. A plain cylinder drifts on air loss; for load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX350STC
- ✓ 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 SI50BX350STC FAQ
Yes, the SI50BX350STC is discontinued. The direct replacement is the SAI50BX350STC. It matches the ISO 15552 mounting interface, 50mm bore, 350mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
It features a G1/4 air port. Force ratings are: 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX350STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX350STC replacement — usually within 7-8 hours.