Anchors and nails were vital to the 16th Century Basque shipbuilding industry, which was one of the world's largest. But the size of anchors was limited by the existing technology, and the making of nails was highly labor-intensive, and therefore very slow. The slitting mill and new uses of existing technologies would eventually provide a solution to both difficulties, but before that occurred, there were several interim solutions attempted by Basque metalworkers.