This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X850, 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 SI50X850
The AirTAC Airtac SI50 Standard Cylinder SI50X850 is a double-acting ISO 15552 (orig. ISO 6431) profile-barrel cylinder with a Ø50mm bore and 850mm stroke, G1/4 air ports and adjustable end cushioning. This model is discontinued — the direct replacement is the SAI50X850, which matches its ISO interface, bore, stroke, force and mounting.
- BoreØ50 mm
- Stroke850 mm
- Port sizeG1/4
- Acting typeDouble acting
- Rod threadM16×1.5
- StatusDiscontinued → SAI50X850
- 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 SI50X850
The AirTAC SI50X850 is a discontinued double-acting ISO 15552 profile cylinder with an 850 mm stroke and 50 mm bore, delivering 982 N push force at 0.5 MPa. The direct replacement is the SAI50X850, matching the exact bore, stroke, G1/4 port, M16x1.5 rod thread and ISO 15552 mounting interface. This non-magnetic SKU cannot accept a sensor.
The SAI upgrade introduces a two Y-shaped one-way piston seal for low start-up pressure and long life, while the SAI family adds SAIL, SAIF and BSAI lock variants the SI lacked. For high heat, Viton H seals raise the temperature limit to 150 C.
Airtac SI50 Standard Cylinder SI50X850 Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X850 |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X850 |
| Bore size | Ø50 mm |
| Stroke | 850 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 SAI50X850 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 SAI50X850 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 SI50X850
| SI | ISO 15552 profile-barrel cylinder (discontinued). |
|---|---|
| 50 | Bore size in mm. |
| ×850 | 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 SI50X850 Is Used
Long-Stroke Diversion
Pushes packages across transfer lines using the 850 mm stroke, relying on the 982 N thrust to overcome friction during routing.
Automated Press Ejection
Clears stamped parts from press beds, utilizing the 30 mm adjustable air cushions to decelerate the payload at stroke end.
Replacing the Airtac SI50 Standard Cylinder SI50X850 with the SAI50X850
To replace the discontinued SI50X850, order the SAI50X850. Verify your ISO 15552 mounting accessory (LB, FA, TC, etc.), the G1/4 air port, and the M16x1.5 rod thread. Because this 850 mm stroke exceeds 300 mm, use an external guide to prevent rod bending and side-load damage. Sizing both ways: the 50 mm bore yields 982 N push at 0.5 MPa, while the neighboring 63 mm bore offers 1559 N. Note that a plain cylinder drifts on air loss; for load holding, use an external rod lock, pilot check valve, or the SAIL/BSAI lock variant. This non-magnet model cannot take a CS1-B/DS1-B sensor.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X850
- ✓ 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 SI50X850 FAQ
Yes, the SI50X850 is discontinued. The direct replacement is the SAI50X850, a current-production ISO 15552 cylinder with the same 50 mm bore, 850 mm stroke, G1/4 port, and mounting interface.
The bore is 50 mm with a G1/4 port. Force output is 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical max of 200 kgf at 1.0 MPa. Speed is 30-800 mm/s.
Request a Quote for the SAI50X850
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X850 replacement — usually within 7-8 hours.