These are not simply SiC tubes. A quick google search for ductile SiC turns up many hits.
As I recall, Rossi was relating the story of how he and Focardi got these tubes serendipitously when visiting a Lab run by the ENEA. They are/were used for plumbing in the liquid fuel reactor R&D and are machinable (with difficulty). The program was abandoned and they essentially "borrowed" the tubes. In fact, it did not occur to me until now but these tubes are probably made with carbon fiber which could play a role in the LENR reaction. BTW - Rossi was not relating this as an idle story. It was part of his tribute to Focardi - Rossi was intending to show by anecdote how the high level connections of Focardi within ENEA, where he was greatly respected - were critical to the success they had. From: Bob Higgins Jones, SiC is a brittle super-hard ceramic and I don't believe Penon could have mistaken a SiC carbide tube for stainless
