Longer term report: still haven't been able to measure the tang, my fridge magnets aren't strong enough to be attracted through the polypropylene handle. Maybe someone with these knives and stronger magnets can try?I'm not going to be able to tell with the ones we got without an X-ray, the polypropylene handle covers everything. The handle is heavier than the blade, if that's any indication. They do show the tang ("espiga") on some of their other models in the catalog.
The polypropylene handles are a bit slippery in use, especially if any oil gets on them. We felt the knives seemed to lose sharpness quickly, I don't know if our expectations were too high, or if it's normal. About 2-3 weeks ago we got a sharpener from the same company which does the trick.