This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X1800STC, 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 SI50X1800STC
The AirTAC SI50 Standard Cylinder SI50X1800STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 1800mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X1800STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke1800 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X1800STC
- 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 SI50X1800STC
The AirTAC SI50X1800STC is a discontinued double-acting ISO 15552 profile cylinder with a 50mm bore and 1800mm stroke. It delivers 982N push and 825N pull at 0.5MPa through a G1/4 port. Because 1800mm exceeds the 1200mm standard maximum for this bore, it is a non-standard made-to-order unit. The direct replacement is the SAI50X1800STC, sharing the exact ISO 15552 mounting interface, force, and TC trunnion mount.
The SAI upgrade features a two Y-shaped one-way piston seal for low start-up pressure and long life. For applications needing load holding, the SAI family adds SAIL and BSAI lock variants the SI lacked. The -S magnet supports CS1-B/DS1-B sensors, and Viton H seals raise operating temps to 150C.
Airtac SI50 Standard Cylinder SI50X1800STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X1800STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X1800STC |
| Bore size | Ø50 mm |
| Stroke | 1800 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 SAI50X1800STC 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 SAI50X1800STC 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 SI50X1800STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×1800 | 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 SI50X1800STC Is Used
Long-Stroke Material Transfer
Pushes workpieces between processing stations over 1800mm distances using the 982N force output.
High-Bay Shuttle Extraction
Extracts totes from deep racking where the TC trunnion mount accommodates the long-rod articulation.
Replacing the Airtac SI50 Standard Cylinder SI50X1800STC with the SAI50X1800STC
To replace the SI50X1800STC, order the SAI50X1800STC. Confirm the ISO 15552 TC trunnion interface, 50mm bore, 1800mm stroke, G1/4 port, and the -S magnet for current AirTAC switches. When sizing, neighboring bores offer different forces: a 40mm bore provides 628N push at 0.5MPa, while a 63mm bore yields 1559N. A plain cylinder drifts without live air, as the cushion only decelerates; use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant for load holding. At 1800mm, the stroke exceeds the 1200mm standard, so external guides are critical to prevent rod bending and side-load damage.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X1800STC
- ✓ 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 SI50X1800STC FAQ
Yes, the SI50X1800STC is discontinued. The direct replacement is the SAI50X1800STC, which shares the same ISO 15552 mounting interface, 50mm bore, 1800mm stroke, G1/4 port, and TC mount.
It has a G1/4 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.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X1800STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X1800STC replacement — usually within 7-8 hours.