This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X25SN, 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 SI50X25SN
The AirTAC Airtac SI50 Standard Cylinder SI50X25SN is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 25mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X25SN, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke25 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X25SN
- 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 SI50X25SN
The AirTAC SI50X25SN is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 25mm stroke. Delivering 982N push force at 0.5MPa, it features a G1/4 port and NBR seals. The direct replacement is the SAI50X25SN, matching the bore, stroke, output force, port and ISO 15552 mounting interface.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life. The original -S magnet supports legacy CS1-B/DS1-B sensors, while the -N NBR seal handles -20 to +70 C.
Airtac SI50 Standard Cylinder SI50X25SN Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X25SN |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X25SN |
| Bore size | Ø50 mm |
| Stroke | 25 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 SAI50X25SN 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 SAI50X25SN 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 SI50X25SN
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×25 | 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 SI50X25SN Is Used
Short-Stroke Clamping
Ideal for holding parts during machining with a compact 25mm stroke and 982N clamping force at 0.5MPa.
Package Diverting
Provides rapid actuation for diverting light packages on a line, operating at speeds between 30-800 mm/s.
Ejector Mechanisms
Suitable for pushing finished goods off conveyor belts where a short, fast 50mm bore motion is required.
Replacing the Airtac SI50 Standard Cylinder SI50X25SN with the SAI50X25SN
To replace the SI50X25SN, order the SAI50X25SN. Confirm the ISO 15552 mounting interface, 50mm bore, 25mm stroke, G1/4 port (PT/G/NPT thread options) and mounting accessory. The -S magnet enables current AirTAC switches (replacing legacy CS1-B/DS1-B), and the -N denotes the NBR seal. Sizing both ways: a 40mm bore yields 628N push at 0.5MPa, while a 63mm bore yields 1559N. Note that a plain cylinder drifts on air loss; the cushion only decelerates. For load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variants.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X25SN
- ✓ 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 SI50X25SN FAQ
Yes, the AirTAC SI50X25SN is discontinued. The direct replacement is the SAI50X25SN. It is dimensionally interchangeable per ISO 15552, retaining the same 50mm bore, 25mm stroke, 982N force, G1/4 port and mounting fixtures.
The 50mm bore features a G1/4 air port. The thrust figures are: 982N push and 825N pull at 0.5MPa, 1374N push at 0.7MPa, 1767N push at 0.9MPa, and a theoretical maximum force of 200kgf at 1.0MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X25SN
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X25SN replacement — usually within 7-8 hours.