(Reposted twice due to server switch)
Looked up a little bit of information on how wood screw threads are cut. Some are "rolled." Have not found much information.

For gimlet point wood screws, from an 1858 patent, with one cutting tool, found here:


http://cool.conservation-us.org/coolaic/sg/wag/Am_Wood_Screws.pdf

(I think the point is that one cutting tool was used, which is shown in three positions. So the tool was
advanced from the right to the left. So for a boolean, the profile would reflect this.