This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX65S, 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 SI50BX65S
The AirTAC Airtac SI50 Standard Cylinder SI50BX65S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 65mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX65S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke65 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX65S
- 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 SI50BX65S
The AirTAC SI50BX65S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 65mm stroke, and a SUS304 stainless piston rod. Delivering 982N push force at 0.5MPa, it is replaced by the SAI50BX65S. This direct upgrade matches the original G1/4 port, M16x1.5 thread, and ISO 15552 mounting interface.
The SAI features an upgraded piston seal with two Y-shaped elements for low start-up pressure. The SI50BX65S includes a magnet for CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants.
Airtac SI50 Standard Cylinder SI50BX65S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX65S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX65S |
| Bore size | Ø50 mm |
| Stroke | 65 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 SAI50BX65S 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 SAI50BX65S 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 SI50BX65S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×65 | 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 SI50BX65S Is Used
Stainless Rod Clamping
Ideal for packaging machines requiring corrosion resistance, using the SUS304 rod to clamp components with a 982N push force at 0.5MPa.
Replacing the Airtac SI50 Standard Cylinder SI50BX65S with the SAI50BX65S
To replace the SI50BX65S, order the SAI50BX65S. It drops into existing fixtures via the identical ISO 15552 mounting interface, matching the 50mm bore, 65mm stroke, G1/4 port, and M16x1.5 rod thread. The -B rod is SUS304 stainless steel, and the -S magnet works with legacy CS1-B/DS1-B switches (the SAI uses current AirTAC switches). For sizing, a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore yields 1559N. The theoretical max is 200kgf at 1.0MPa. Note that a standard 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 → SAI50BX65S
- ✓ 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 SI50BX65S FAQ
Yes, the SI50BX65S is discontinued. The direct replacement is the SAI50BX65S. It shares the same ISO 15552 mounting interface, 50mm bore, 65mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The G1/4 port bore delivers a push force of 982N and pull of 825N at 0.5MPa. At 0.7MPa push is 1374N, and the theoretical max force is 200kgf at 1.0MPa. Operating pressure is 0.15-1.0MPa, with a speed range of 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX65S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX65S replacement — usually within 7-8 hours.