from
http://titanicarchive-online.com/index.php4?page=319
Researchers from the National Institute for Standards and Technology and John Hopkins University favor the weak rivet theory. They found that most of the rivets recovered from RMS Titanic also contained excessive amounts of slag that made them more brittle, and therefore, more likely to snap off at the head upon impact with the iceberg. Their analyses of steel hull plate indicated, however, that "it is possible that brittle steel contributed to the damage at the bow due to the impact with the iceberg, but much more likely that the brittle steel was a factor in the breakup of the ship at the surface" (Foecke 1998:14).
After reviewing and debating the results from these investigations, the Marine Forensics Panel (SD-7) in a 1997 report to the Society of Naval Architects and Marine Engineers concluded that the cause of sinking was in large part due to the failure of the rivets that fastened together its hull. Metallurgical analyses are continuing at the National Institute of Standards and Technology and John Hopkins University. The results of these additional analyses may shed better light on the influence of steel and rivets on the sinking of RMS Titanic during that dark night of April 14, 1912.
**disclaimer my Dad was a contributing engineer on the project....