This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X270S, 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 SI50X270S
The AirTAC Airtac SI50 Standard Cylinder SI50X270S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 270mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X270S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke270 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X270S
- 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 SI50X270S
The AirTAC SI50X270S is a discontinued double-acting ISO 15552 profile cylinder featuring a 50mm bore, 270mm stroke, and a G1/4 air port. It delivers 982 N push force at 0.5 MPa. AirTAC replaced this legacy unit with the SAI50X270S, a direct replacement retaining the exact ISO 15552 mounting interface, bore, stroke, output force, and port size.
The SAI upgrade introduces an advanced piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. The -S suffix denotes a piston magnet for legacy CS1-B/DS1-B sensors, and Viton H seals can raise the operating temperature to 150 C.
Airtac SI50 Standard Cylinder SI50X270S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X270S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X270S |
| Bore size | Ø50 mm |
| Stroke | 270 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 SAI50X270S 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 SAI50X270S 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 SI50X270S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×270 | 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 SI50X270S Is Used
Package Diversion
Actuates routing gates on packaging lines, using the 270mm stroke to push cartons cleanly between parallel conveyors.
Pallet Handling
Drives lifting forks or alignment stops in automated storage systems, providing 982 N of push force at 0.5 MPa.
Clamp Actuation
Secures workpieces in CNC machining fixtures, where the G1/4 port and adjustable cushions ensure smooth operation.
Replacing the Airtac SI50 Standard Cylinder SI50X270S with the SAI50X270S
To replace the SI50X270S, order the SAI50X270S and confirm the ISO 15552 mounting interface, 50mm bore, 270mm stroke, G1/4 port (PT/G/NPT), and mounting accessory. The -S magnet enables CS1-B/DS1-B switches, though the SAI family uses current AirTAC sensors. Sizing both ways: a neighbouring 63mm bore yields 1559 N push at 0.5 MPa, while dropping to 40mm provides 628 N. Because the 270mm stroke exceeds 300mm is false here, but always ensure adequate guide support to prevent rod bending under side loads. A plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external pilot check valve or explore the SAIL lock and BSAI clamp-lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X270S
- ✓ 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 SI50X270S FAQ
Yes, the SI50X270S is discontinued. The direct replacement is the SAI50X270S. It shares the same ISO 15552 mounting interface, 50mm bore, 270mm stroke, output force, and G1/4 port, fitting existing fixtures perfectly.
This double-acting cylinder has a G1/4 air port. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X270S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X270S replacement — usually within 7-8 hours.