Boil away the jargon and it means that bolts work by clamping things together under tension and that both the connection and the bolt must be strong enough resist any force that tries to break that connection or the bolt that’s holding it together.Before we go much further let me point out that while there are formal definitions that distinguish bolts from screws, it’s a lot easier (and just as cor- rect in an informal setting) to use either term to describe threaded fasteners, so unless we need to identify a particular type of fastener, such as sheet metal screw or Allen head bolt, we’ll use the terms screw and bolt interchangeably.How Bolts Work Steel, no matter what its composition, is elastic, and when a load is applied to it in tension, it stretches; like any other spring, the further it’s stretched, the more it resists.Think of bolts as very stiff springs, and you’ll have the gist of it.Most can meet either the ASTM A194, ASTM A563, or ASTM F594 standard.Early nuts were made of wood and were used with wooden pegs.
In 1770, English instrument maker, Jesse Ramsden (1735-1800) invented the first satisfactory screw-cutting lathe. In 1797, Englishmen, Henry Maudslay (1771-1831) invented a large screw-cutting lathe that made it possible to mass-produce accurately sized screws.
The timestamp is only as accurate as the clock in the camera, and it may be completely wrong.
A screw is any shaft with a corkscrew-shaped groove formed on its surface. A screwdriver is a tool for driving (turning) screws; screwdrivers have a tip that fits into the head of a screw.
In technical terms, the job of a threaded fastener is to apply a comprehensive force to a connection, creating a joint strong enough to oppose any static, tensile, and dynamic loads that may be placed upon it.
By that same token, the fastener(s) used must also be capable of resisting impact, shock, vibration, shear, bend, torque and vector (angular) forces, as well as other compressive loads.