A screw is any rod that has a corkscrew groove in its surface. Screws are used to hold two objects together. A screwdriver is a tool that turns (turns) a screw; A screwdriver has a point that fits over the head of a screw.Early screw
Spiral tools became common around the first century AD, but historians don't know who invented them first. Early screws were made from wood and were used in wine presses, olive oil presses, and pressing clothes. The metal screws and nuts used to hold two things together first appeared in the fifteenth century.
In 1770, English toolmaker Jesse Ramsden (1735–1800) invented the first satisfactory screw-cutting lathe and became an inspiration to other inventors. In 1797, Englishman Henry Maudslay (1771-1831) invented a large screw-cutting lathe that could be used to mass-produce screws of precise dimensions. In 1798, the American mechanic David Wilkinson (1771-1652) also invented a machine for the mass production of metal-threaded screws.Robertson screw
In 1908, Canadian P. L. Robertson (1879-1951) invented the square-drive screw, 28 years before Henry Phillips applied for a patent on his Phillips-head screw, which is also a screw with square shank. The Robertson screw is considered "the first grooved fastener available for manufacturing use". The design became a North American standard published in the Industrial Fastener Standards Book. The square head on the screw is an improvement over the slotted head because the screwdriver does not slip out of the screw head during installation. An early 20th century Model T built by Ford Motor Company (one of Robertson's early customers) used over seven hundred Robertson propellers.Phillips screws and other enhancements
In the early 1930s, Oregon businessman Henry Phillips (1889–1958) invented the Phillips screw. Automakers now use car assembly lines. They need screws that can handle higher torques and provide tighter tightening. Phillips head screws are compatible with automatic screwdrivers used on assembly lines.
The hex or hex head of a screw has a hex hole that can be turned with a hex wrench. A hex wrench (or hex wrench) is a hexagonal-shaped turning tool (wrench) originally manufactured by William G. Allen of the Allen Manufacturing Company in Connecticut; the question of who first patented it is debatable.
In 1744, the flat-bladed staple drill was invented, the forerunner of the first simple screwdriver. Hand screwdrivers first appeared after 1800.Screw types
Countless types of propellers have been invented to perform specific tasks.
There are many tools that allow you to drive screws into the material to be fixed. Hand tools used to drive slotted and Phillips screws are called screwdrivers. A power tool that does the same job is a screwdriver. Hand tools used to drive cap bolts and other types are called wrenches (used in the UK) or spanners (used in the US).
A nut is a square, round, or hexagonal piece of metal with internal threads. Nuts help hold things together and are used with screws or bolts.Sources and additional information