Okay so the pun is overused, BUT, I have been trying to finish this tiny little drawing for months, and still have not finished it.  This is drawn using a basic Ticonderoga pencil in my moleskin sketchbook (it’s about 5×7-ish).  This actually is a large carriage bolt, not a screw, but I just couldn’t resist the title.  I am attempting to render it in a realistic fashion, if I ever get the time and patience (and focus) to do so.