Before the frame can be welded holes need to be drilled and tapped to attach the stainless steel runners and holes need to be drilled on the underside to receive the leveling bolts. That's 54 5/16 ...

As a result, stainless steel bolts of all sizes cost considerably more than galvanized steel bolts. In 2011 galvanized bolts ranging from one quarter to one half inch in diameter and from 1 to 4 ...