This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X900STC, 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 SI50X900STC
The AirTAC Airtac SI50 Standard Cylinder SI50X900STC is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 900mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X900STC, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke900 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X900STC
- 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 SI50X900STC
The AirTAC SI50X900STC is a discontinued double-acting ISO 15552 profile cylinder with a 900 mm stroke and TC trunnion mount. It delivers 982 N push and 825 N pull at 0.5 MPa through a G1/4 port. AirTAC replaced this legacy unit with the SAI50X900STC, a direct sharing the exact bore, stroke, force, port and ISO 15552 mounting interface.
The SAI upgrade features two Y-shaped one-way piston seals for low start-up pressure and long life. The SAI family also adds SAIL, SAIF and BSAI lock variants the SI lacked. Your -S magnet works with legacy CS1-B/DS1-B sensors.
Airtac SI50 Standard Cylinder SI50X900STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X900STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X900STC |
| Bore size | Ø50 mm |
| Stroke | 900 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 SAI50X900STC 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 SAI50X900STC 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 SI50X900STC
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×900 | 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 SI50X900STC Is Used
Long-Stroke Material Transfer
Drives goods across wide conveyor gaps with 982 N push at 0.5 MPa, utilizing the 900 mm extension to bridge distant workstations.
Pallet Push-Off Station
Indexes packaged loads onto outbound rollers, relying on the TC trunnion mount to pivot safely under shifting dynamic loads.
Elevated Platform Lowering
Lowers light fixtures or tooling plates over the 900 mm travel, requiring external guides to prevent rod bending during descent.
Replacing the Airtac SI50 Standard Cylinder SI50X900STC with the SAI50X900STC
To replace the SI50X900STC, order the SAI50X900STC. Confirm the ISO 15552 TC trunnion interface, 50 mm bore, 900 mm stroke, G1/4 port (PT/G/NPT thread options) and the -S magnet for CS1-B/DS1-B switches. Sizing both ways: a 63 mm bore yields 1559 N push at 0.5 MPa, while a 40 mm bore yields 628 N. At 900 mm, prevent rod bending by adding an external guide to absorb side loads. A plain cylinder drifts on air loss; for load holding use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X900STC
- ✓ 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 SI50X900STC FAQ
Yes, the SI50X900STC is discontinued. The direct replacement is the SAI50X900STC. It shares the identical ISO 15552 mounting interface, 50 mm bore, 900 mm stroke, output force, G1/4 port and TC trunnion mount, fitting directly into existing fixtures.
This double-acting cylinder has a G1/4 air port and M16x1.5 rod thread. It generates 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 of 200 kgf at 1.0 MPa. Speed is 30-800 mm/s.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X900STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X900STC replacement — usually within 7-8 hours.