This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X120S, 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 SI50X120S
The AirTAC Airtac SI50 Standard Cylinder SI50X120S 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 SAI50X120S, 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 → SAI50X120S
- 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 SI50X120S
The AirTAC SI50X120S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 120mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X120S, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade features a modernized piston seal using two Y-shaped one-way elements for low start-up pressure and extended life. You can also spec rod materials like SUS304 (B) or seals such as Viton H for 0-150C heat.
Airtac SI50 Standard Cylinder SI50X120S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X120S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X120S |
| 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 SAI50X120S 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 SAI50X120S 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 SI50X120S
| 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 SI50X120S Is Used
Package Diverting
Actuates routing gates on packaging lines using its 120mm stroke and 982N push force to redirect moderate-weight cartons reliably.
Clamp Actuation
Secures workpieces during machining operations, providing stable 825N pull force to hold parts firmly against vibration.
Replacing the Airtac SI50 Standard Cylinder SI50X120S with the SAI50X120S
To replace the SI50X120S, order the SAI50X120S and confirm your ISO 15552 mounting accessory (LB, FA, TC, etc.), G1/4 port thread (PT/G/NPT), and the -S magnet for legacy CS1-B/DS1-B sensors. The SAI family also introduces lock variants the SI lacked: SAIL for air-released locking and BSAI for clamp-locking. Remember, a standard cylinder drifts on air loss; the cushion only decelerates, so use a pilot check valve or lock variant for held loads. If sizing up or down, note the 40mm bore yields 628N push @0.5MPa, while the 63mm bore yields 1559N.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X120S
- ✓ 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 SI50X120S FAQ
Yes, the SI50X120S is discontinued. The direct replacement is the SAI50X120S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 120mm stroke, output force, G1/4 port, and mounting interface.
This 50mm bore cylinder features a G1/4 air port and M16x1.5 rod thread. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X120S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X120S replacement — usually within 7-8 hours.