This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX120S, 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 SI50AX120S
The AirTAC Airtac SI50 Standard Cylinder SI50AX120S 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 SAI50AX120S, 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 → SAI50AX120S
- 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 SI50AX120S
The AirTAC SI50AX120S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 120mm stroke, and an SUS420J2 stainless steel rod. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50AX120S, which shares identical mounting, force, and porting.
The SAI upgrade features a new two Y-shaped one-way piston seal for low start-up pressure and long life. The -S magnet works with legacy CS1-B/DS1-B sensors, while the SAI family adds SAIL, SAIF, and BSAI lock variants the SI lacked.
Airtac SI50 Standard Cylinder SI50AX120S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX120S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX120S |
| 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 SAI50AX120S 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 SAI50AX120S 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 SI50AX120S
| 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 SI50AX120S Is Used
Diverting Gate Actuation
Provides robust 982 N push force to pivot heavy sorting gates on packaging lines, with the 120mm stroke ensuring full lane clearance.
Stainless Rod Ejection
The SUS420J2 rod resists moisture in washdown environments, reliably pushing cartons off accumulation rollers without corrosion.
Vertical Press Damping
Moves a 50 kg tooling head downward; the adjustable 30mm air cushions absorb kinetic energy smoothly at the stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50AX120S with the SAI50AX120S
To replace this SI50AX120S, order the SAI50AX120S and confirm the ISO 15552 interface, 50mm bore, 120mm stroke, G1/4 port, and the SUS420J2 stainless rod (-A). The built-in magnet (-S) accepts legacy CS1-B/DS1-B switches, though the SAI uses current AirTAC sensors. If you need more force, the neighbouring 63mm bore provides 1559 N push at 0.5 MPa; if less is required, the 40mm bore offers 628 N. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX120S
- ✓ 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 SI50AX120S FAQ
Yes, the AirTAC SI50AX120S is discontinued. The direct replacement is the SAI50AX120S. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 120mm stroke, G1/4 port, and mounting interface.
The bore features a G1/4 air port. At 0.5 MPa it provides 982 N push and 825 N pull force. At 0.7 MPa push is 1374 N, and at 0.9 MPa it is 1767 N. The theoretical maximum force is 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX120S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX120S replacement — usually within 7-8 hours.