This model is discontinued
AirTAC has phased out the SI series. You can still order this code here: we ship the direct replacement SAI50X850STC, 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 SI50X850STC
The AirTAC Airtac SI50 Standard Cylinder SI50X850STC 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 SAI50X850STC, 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 → SAI50X850STC
- 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 SI50X850STC
The AirTAC SI50X850STC is a discontinued double-acting ISO 15552 profile cylinder with an 850 mm stroke and TC trunnion mount. Delivering 982 N push force at 0.5 MPa, it features a G1/4 air port, M16x1.5 rod thread, and 30 mm adjustable air cushions. The direct replacement is the SAI50X850STC, which shares the same ISO 15552 mounting interface, bore, stroke, and output force.
The SAI upgrade introduces a refined piston seal with two Y-shaped one-way elements for low start-up pressure and extended life. For load holding, note that a standard cylinder drifts without live air—the cushion only decelerates—so use the SAIL lock or BSAI clamp-lock variants if needed. This -S SKU uses legacy CS1-B/DS1-B sensors, while the SAI takes current AirTAC switches.
Airtac SI50 Standard Cylinder SI50X850STC Technical Specifications
| Model | Airtac SI50 Standard Cylinder SI50X850STC |
|---|---|
| Series | SI ISO 15552 profile cylinder (discontinued) |
| Replacement | SAI50X850STC |
| 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 SAI50X850STC 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 SAI50X850STC 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 SI50X850STC
| 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 SI50X850STC Is Used
Long-Stroke Diversion
Actuates routing gates on packaging lines, using the 850 mm stroke to shift products between parallel conveyors.
Guided Push Assembly
Drives long-travel press fixtures, requiring external linear guides to prevent rod bending over the 850 mm extension.
Replacing the Airtac SI50 Standard Cylinder SI50X850STC with the SAI50X850STC
To replace the SI50X850STC, order the SAI50X850STC. Verify the ISO 15552 TC trunnion interface, 50 mm bore, 850 mm stroke, G1/4 port, and the -S magnet for switch sensing. If you need to size both ways, the neighbouring 40 mm bore yields 628 N push at 0.5 MPa, whereas the 63 mm bore provides 1559 N. For this 850 mm long stroke, add external guides to prevent rod bending and side-load damage. A plain cylinder does not hold load on air loss; the cushion only decelerates. For secure holding, specify the SAIL air-released lock, the BSAI clamp-lock, or an external pilot check valve.
Replacement checklist
- ✓ Same ISO 15552 interface → SAI50X850STC
- ✓ 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 SI50X850STC FAQ
Yes, the SI50X850STC is discontinued. The direct replacement is the SAI50X850STC. It is dimensionally interchangeable per ISO 15552, matching the 50 mm bore, 850 mm stroke, TC mount, G1/4 port, and output force.
This double-acting cylinder has a G1/4 air port. It delivers 982 N push and 825 N pull at 0.5 MPa, 1374 N push at 0.7 MPa, and a theoretical maximum force of 200 kgf at 1.0 MPa.
Related AirTAC SAI Cylinders
Request a Quote for the SAI50X850STC
Send us the quantity and destination. We confirm price, stock and lead time on the SAI50X850STC replacement — usually within 7-8 hours.