This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X225, 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 SI50X225
The AirTAC Airtac SI50 Standard Cylinder SI50X225 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 225mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X225, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke225 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X225
- 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 SI50X225
The AirTAC SI50X225 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 225mm stroke. It delivers a push force of 982 N at 0.5 MPa via a G1/4 port. AirTAC replaced this legacy unit with the SAI50X225, a direct upgrade retaining the exact ISO 15552 mounting interface, bore, stroke, output force, port and mounting accessories.
The SAI upgrade features a modernized piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For applications needing load holding on air loss, the SAI family introduces SAIL and BSAI lock variants absent in the SI line. This specific SKU lacks a magnet, so it cannot accept position sensors.
Airtac SI50 Standard Cylinder SI50X225 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X225 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X225 |
| Bore size | Ø50 mm |
| Stroke | 225 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 SAI50X225 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 SAI50X225 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 SI50X225
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×225 | 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 SI50X225 Is Used
Package Diverting
Pushes medium-weight cartons off a main conveyor line using the 982 N thrust at 0.5 MPa.
Pallet Stop Gate
Acts as a pneumatic stop for incoming pallets, absorbing impact with its 30mm adjustable air cushion.
Component Clamping
Secures workpieces during machining, providing a safe 589 N working load for fixturing tasks.
Replacing the Airtac SI50 Standard Cylinder SI50X225 with the SAI50X225
To replace the SI50X225, order the SAI50X225 direct equivalent, confirming the ISO 15552 mounting interface, 50mm bore, 225mm stroke, G1/4 port (PT/G/NPT thread options) and your mounting accessory (LB, FA, TC, etc.). Because this 225mm stroke exceeds 300mm? No, but at 225mm you should still verify guide alignment to prevent rod bending under side loads. Sizing both ways: a neighbouring 40mm bore yields 628 N push at 0.5 MPa, while a 63mm bore provides 1559 N. A plain cylinder does not hold load without live air; the cushion only decelerates. For load holding, use an external pilot check valve, rod lock, or the SAIL/BSAI variants. Since this SKU has no magnet (-S), it cannot support CS1-B/DS1-B sensors.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X225
- ✓ 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 SI50X225 FAQ
Yes, the SI50X225 is discontinued. The direct replacement is the AirTAC SAI50X225. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 225mm stroke, G1/4 port and mounting interface.
This double-acting cylinder uses a G1/4 port. It delivers a push force of 982 N and pull of 825 N at 0.5 MPa, 1374 N at 0.7 MPa, and a theoretical max of 200 kgf at 1.0 MPa.
Request a Quote for the SAI50X225
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X225 replacement — usually within 7-8 hours.