This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X125, 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 SI50X125
The AirTAC Airtac SI50 Standard Cylinder SI50X125 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 125mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X125, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke125 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X125
- 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 SI50X125
The AirTAC SI50X125 is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 125mm stroke. It delivers 982N push force at 0.5MPa via a G1/4 port. The direct replacement is the SAI50X125, which shares identical mounting, bore, stroke, force and port dimensions.
The SAI upgrade introduces a two Y-shaped one-way piston seal for lower start-up pressure and longer life. This non-magnet SKU cannot take a sensor, unlike CS1-B/DS1-B equipped units. For high heat, Viton H seals raise the temperature limit to 150C.
Airtac SI50 Standard Cylinder SI50X125 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X125 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X125 |
| Bore size | Ø50 mm |
| Stroke | 125 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 SAI50X125 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 SAI50X125 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 SI50X125
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×125 | 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 SI50X125 Is Used
Package Diverting
Ideal for pushing medium-weight cartons off a packaging line using the 982N thrust at 0.5MPa.
Pallet Stop Gate
Acts as a reliable 125mm stroke stopper for pallets entering a stretch wrapper station.
Clamp Actuation
Provides consistent clamping pressure for machining medium aluminum housings.
Replacing the Airtac SI50 Standard Cylinder SI50X125 with the SAI50X125
To replace the SI50X125, order the SAI50X125 direct: verify the ISO 15552 mounting interface, 125mm stroke, G1/4 port (PT/G/NPT thread options) and your mounting accessory (LB, FA, TC, etc.). Because this SKU lacks the -S magnet, it cannot accept CS1-B/DS1-B sensors—order an -S variant if position detection is needed. Sizing both ways: a 40mm bore gives 628N push at 0.5MPa, while a 63mm bore yields 1559N. A plain cylinder drifts on air loss—the cushion only decelerates—so use an external pilot check valve or the SAIL/BSAI lock variant for load holding. The SAI family also adds the SAIF self-valve option.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X125
- ✓ 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 SI50X125 FAQ
Yes, the SI50X125 is discontinued. The direct replacement is the SAI50X125. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 125mm stroke, 982N force and G1/4 port to fit existing fixtures.
It features a G1/4 air port and provides 982N push / 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical max of 200kgf at 1.0MPa. Speed is 30-800mm/s.
Request a Quote for the SAI50X125
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X125 replacement — usually within 7-8 hours.