This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX325S, 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 SI50BX325S
The AirTAC Airtac SI50 Standard Cylinder SI50BX325S is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 325mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50BX325S, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke325 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50BX325S
- 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 SI50BX325S
The AirTAC SI50BX325S is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 325mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50BX325S, matching the interface, force, and stroke.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure. This SUS304 rod (-B) variant includes a magnet (-S) for CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50BX325S Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX325S |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX325S |
| Bore size | Ø50 mm |
| Stroke | 325 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 SAI50BX325S 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 SAI50BX325S 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 SI50BX325S
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×325 | 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 SI50BX325S Is Used
Package Diverting
Drives diverter arms on sorting lines, utilizing the 325mm stroke to push parcels cleanly between adjacent belt lanes.
Machine Guard Gates
Actuates safety access doors on CNC enclosures, with the SUS304 rod providing corrosion resistance in coolant environments.
Replacing the Airtac SI50 Standard Cylinder SI50BX325S with the SAI50BX325S
To replace the SI50BX325S, order the SAI50BX325S. Verify the ISO 15552 mounting, 50mm bore, 325mm stroke, G1/4 port, and -S magnet. Sizing down, a 40mm bore yields 628N at 0.5MPa; sizing up, a 63mm bore yields 1559N. For the 325mm stroke, use external guides to prevent rod bending. The cushion only decelerates; for load holding on air loss, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX325S
- ✓ 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 SI50BX325S FAQ
Yes, the SI50BX325S is discontinued. The direct replacement is the SAI50BX325S. It is dimensionally interchangeable per ISO 15552, retaining the exact 50mm bore, 325mm stroke, 982N force, G1/4 port, and mounting interface.
The G1/4 port bore 50mm cylinder provides 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, and a theoretical max of 200kgf at 1.0MPa. It operates at 30-800mm/s with a 30mm adjustable cushion.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX325S
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX325S replacement — usually within 7-8 hours.