` ::: Umm, neither of those examples is actually correct. On metalworking machinery, they are dovetail *slides*. They don't join. They make a sliding fit which is resistant to lifting. You can achieve the same effect with box ways by putting a sliding surface along the opposite side from the main bearing surface, but a dovetail is cheaper to make. In turbines, they are not called dovetails and they are not the same shape. They are called ``christmas trees`` in the shop, my aging brain has forgotten the correct technical term. But it ain't ``dovetail.`` They are shaped like an upside-down christmas tree with NO SHARP CORNERS. The principal is similar but not the same as a dovetail. Also, in general they are once again not a tight fit. They have to have a fair amnount of clearance to account for large temperature variations. In operation they actually rattle around some. So once again, as this article is mostly about permanent or semi-permanent joints, the use in turbines and metalworking equipment does not seem applicable.   `