This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX120S, 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 SI50BX120S
The AirTAC Airtac SI50 Standard Cylinder SI50BX120S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 120mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX120S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke120 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX120S
- 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 SI50BX120S
The AirTAC SI50BX120S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 120mm stroke, and a SUS304 stainless steel rod. Delivering 982 N push force at 0.5 MPa, it is replaced by the SAI50BX120S. This direct successor shares the exact ISO 15552 mounting interface, G1/4 port, and 30mm cushions.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. For sensing, the -S magnet works with legacy CS1-B/DS1-B switches. For high heat, Viton H seals raise the limit to 150 C.
Airtac SI50 Standard Cylinder SI50BX120S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX120S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX120S |
| Bore size | Ø50 mm |
| Stroke | 120 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 SAI50BX120S 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 SAI50BX120S 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 SI50BX120S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×120 | 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 SI50BX120S Is Used
Stainless Rod Diverter
Ideal for washdown conveyor diverters where the SUS304 rod resists moisture while pushing 982 N packages at 0.5 MPa.
Corrosive Fluid Clamp
Holds chemical processing fixtures securely, leveraging the stainless piston rod to prevent corrosion in harsh environments.
Replacing the Airtac SI50 Standard Cylinder SI50BX120S with the SAI50BX120S
To replace the SI50BX120S, order the SAI50BX120S. Confirm the ISO 15552 mounting interface, G1/4 port, M16x1.5 thread, and the -S magnet for CS1-B/DS1-B sensors. The SUS304 rod suits corrosive settings. If sizing up, the 63mm bore yields 1559 N at 0.5 MPa; sizing down, the 40mm bore yields 628 N. Note: a plain cylinder drifts on air loss as cushions only decelerate. For held loads, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX120S
- ✓ 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 SI50BX120S FAQ
Yes, the SI50BX120S is discontinued. The direct replacement is the SAI50BX120S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 120mm stroke, G1/4 port, and mounting interface.
The G1/4 port bore delivers a push of 982 N and pull of 825 N at 0.5 MPa. At 0.7 MPa push is 1374 N, and the theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX120S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX120S replacement — usually within 7-8 hours.