This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50AX425, 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 SI50AX425
The AirTAC SI50 Standard Cylinder SI50AX425 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 425mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50AX425, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke425 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50AX425
- 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 SI50AX425
The AirTAC SI50AX425 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 425mm stroke. It delivers 982 N push force at 0.5 MPa via a G1/4 port. The direct replacement is the SAI50AX425, matching the interface, force, and mounting exactly.
This SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. This SKU lacks a magnet (-S) and cannot take a sensor. The -A rod is SUS420J2 stainless.
Airtac SI50 Standard Cylinder SI50AX425 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50AX425 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50AX425 |
| Bore size | Ø50 mm |
| Stroke | 425 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 SAI50AX425 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 SAI50AX425 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 SI50AX425
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×425 | 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 SI50AX425 Is Used
Long-Stroke Diverting
Drives packaging lane diverters over a 425 mm travel distance, utilizing the 982 N push force to shift products reliably at speed.
Material Lowering
Controls the descent of light fixtures or platens up to 50 kg, relying on adjustable air cushions to decelerate the load at stroke end.
Corrosive Washdown
Ideal for food or chemical processing lines thanks to the SUS420J2 stainless steel rod option, resisting rust in humid washdown environments.
Replacing the Airtac SI50 Standard Cylinder SI50AX425 with the SAI50AX425
To replace the SI50AX425, order the SAI50AX425. Verify your ISO 15552 mounting (LB, FA, TC, etc.), the G1/4 port, and the M16x1.5 rod thread. Because this 425 mm stroke exceeds 300 mm, use an external guide to prevent rod bending and side-load wear. If you need more force than the 50 mm bore provides at 0.5 MPa, step up to a 63 mm cylinder. Note that a plain cylinder drifts on air loss—the cushion only decelerates. For load holding, use an external pilot check valve or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50AX425
- ✓ 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 SI50AX425 FAQ
Yes, the AirTAC SI50AX425 is discontinued. The direct replacement is the SAI50AX425. It is dimensionally interchangeable per ISO 15552, retaining the same 50 mm bore, 425 mm stroke, output force, G1/4 port, and mounting accessories.
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, 1767 N push at 0.9 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50AX425
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50AX425 replacement — usually within 7-8 hours.