Talk about coincidence! Got home yesterday and Roy Underhill's latest book had arrived. I had pre-ordered it a couple of months ago, and had actually forgot about it. Anyway, the book is "The Woodwright's Guide" and it has a whole section on making wooden screws...BIG wooden screws...like on a vise, or maybe a cider press? I know this is a blacksmith site, and you seem to be leaning toward large metal screws, but I have seen cider presses with wooden screws. Just a thought...bart