The nail


Without nails, civilization would surely crumble. This key invention dates back more than 2,000 years to the Ancient Roman period, and became possible only after humans developed the ability to cast and shape metal. Previously, wood structures had to be built by interlocking adjacent boards geometrically a much more arduous construction process.

Until the 1790s and early 1800s, hand-wrought nails were the norm, with a blacksmith heating a square iron rod and then hammering it on four sides to create a point, according to the University of Vermont. Nail-making machines came online between the 1790s and the early 1800s. Technology for crafting nails continued to advance; After Henry Bessemer developed a process to mass-produce steel from iron, the iron nails of yesteryear slowly waned and by 1886, 10 percent of U.S. nails were created from soft steel wire, according to the University of Vermont. By 1913, 90 percent of nails produced in the U.S. were steel wire.

Meanwhile, the screw a stronger but harder-to-insert fastener is thought to have been invented by the Greek scholar Archimedes in the third century B.C.