This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X275S, 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 SI50X275S
The AirTAC SI50 Standard Cylinder SI50X275S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 275mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X275S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke275 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X275S
- 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 SI50X275S
The AirTAC SI50X275S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 275mm stroke. Delivering 982N push force at 0.5MPa via a G1/4 port, it is replaced by the direct replacement SAI50X275S. The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life, while the SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked.
This SI50X275S includes a piston magnet for CS1-B/DS1-B switches. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI variant.
Airtac SI50 Standard Cylinder SI50X275S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X275S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X275S |
| Bore size | Ø50 mm |
| Stroke | 275 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 SAI50X275S 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 SAI50X275S 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 SI50X275S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×275 | 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 SI50X275S Is Used
Package Diversion
Actuates sorting gates on packaging lines using the 982N push force at 0.5MPa to deflect cartons reliably.
Pallet Stopper
Deploys a physical stop block for pallets on roller conveyors, utilizing the 30mm adjustable air cushion for smooth stops.
Replacing the Airtac SI50 Standard Cylinder SI50X275S with the SAI50X275S
To replace the SI50X275S, order the SAI50X275S. It is dimensionally interchangeable per ISO 15552, matching the 50mm bore, 275mm stroke, G1/4 port, M16x1.5 rod thread and mounting fixtures. Retain the -S magnet for current AirTAC switches (legacy CS1-B/DS1-B). Sizing both ways: a 40mm bore yields 628N push @0.5MPa, while a 63mm bore yields 1559N. At 0.7MPa this 50mm bore reaches 1374N. Because the 275mm stroke exceeds 300mm is false here, but always ensure guide alignment to prevent rod bending. For dead-load holding, select the SAIL or BSAI lock variant, as standard cushions only decelerate.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X275S
- ✓ 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 SI50X275S FAQ
Yes, the AirTAC SI50X275S is discontinued. The direct replacement is the SAI50X275S. It shares the identical ISO 15552 mounting interface, 50mm bore, 275mm stroke, force, G1/4 port and mounting accessories, fitting existing fixtures perfectly.
The 50mm bore features a G1/4 port. It delivers 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200 kgf at 1.0 MPa. Speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X275S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X275S replacement — usually within 7-8 hours.