Good looking screw there! I'm not sure about what was done here, but one way to go is creating a helix, extruding it and welding the appropriate verts.
Yep, it's never worked for me either. At least not after 2010, if I recall correctly. I've gotten into the habit of extruding and welding. Pain in the ass.
Well i created lines converted them to editable poly and spaced them.Each section is a differnt polygon.Theres no extrude on anything.Basicly 2d block out.