MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Steel sheet metal screw. Screws were not manufactured until the early 19th century although the helical screw was known from Ancient Greece. The Archimedes screw, not a fastener, was designed to raise water. The sheet metal screw is used to joint plastic, metal and wood.
Model release not required. Property release not required.