buttress thread
noun
a screw thread having one flank that is vertical while the other is inclined, and a flat top and bottom: used in machine tools and designed to withstand heavy thrust in one direction
Words nearby buttress thread
buttonwood,
buttony,
buttress,
buttress plate,
buttress root,
buttress thread,
butts and bounds,
buttstock,
buttstrap,
butty,
butuan