This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50BX325, 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 SI50BX325
The AirTAC Airtac SI50 Standard Cylinder SI50BX325 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 SAI50BX325, 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 → SAI50BX325
- 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 SI50BX325
The AirTAC SI50BX325 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore, 325mm stroke, and SUS304 stainless piston rod. Generating 982N push force at 0.5MPa, it is replaced by the SAI50BX325—a direct sharing the same interface, G1/4 port, and force. The SAI upgrades the piston seal to two Y-shaped one-way elements for low start-up pressure and long life.
Because this SKU lacks a magnet, it cannot accept a position switch. If you need load holding on air loss, step up to the SAIL or BSAI lock variants, as standard cushions only decelerate.
Airtac SI50 Standard Cylinder SI50BX325 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50BX325 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50BX325 |
| 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 SAI50BX325 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 SAI50BX325 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 SI50BX325
| 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 SI50BX325 Is Used
Stainless Rod Actuation
Ideal for packaging or washdown stations where the SUS304 rod resists moisture while pushing loads up to 589N safely.
Long Stroke Lowering
The 325mm stroke handles material descent tasks, but external guides are critical here to prevent rod bending under side loads.
Transfer Diversion
Provides reliable 50mm bore thrust for diverting medium-weight goods, using the G1/4 port for rapid 30-800mm/s cycling.
Replacing the Airtac SI50 Standard Cylinder SI50BX325 with the SAI50BX325
To replace the SI50BX325, order the SAI50BX325. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 air port, and the M16x1.5 rod thread. The -B rod material is SUS304 stainless steel, offering superior corrosion resistance versus the standard carbon steel. Sizing checks: a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore yields 1559N. For the 325mm stroke, use external guides to prevent rod bending and side-load damage. This non-magnetic SKU cannot take sensors; if you need position feedback, select an SAI50X325S and use current AirTAC switches. Remember, a standard cylinder drifts without air; for secure load holding, use the SAIL lock or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50BX325
- ✓ 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 SI50BX325 FAQ
Yes, the SI50BX325 is discontinued. The direct replacement is the SAI50BX325. It shares the exact ISO 15552 mounting interface, 50mm bore, 325mm stroke, G1/4 port, and output force, fitting existing fixtures perfectly.
The G1/4 port feeds a 20mm rod. Force ratings are: 982N push and 825N pull at 0.5MPa; 1374N push at 0.7MPa; 1767N push at 0.9MPa; with a theoretical max of 200kgf at 1.0MPa. Operating speed is 30-800mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50BX325
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50BX325 replacement — usually within 7-8 hours.