pliers |
saw |
top 10 words in brain distribution (in article): form shoe design material jewellery metal hand piece ancient process |
top 10 words in brain distribution (in article): blade steel cut tool hand modern edge type material power |
top 10 words in brain distribution (not in article): tea tooth pearl kite culture type time century wear shape |
top 10 words in brain distribution (not in article): iron head handle hair metal design nail size whip breast |
times more probable under pliers 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under saw (words not in the model) | |
History. Pliers in the general sense are an ancient and simple invention, no singular point in history or singular inventor can be credited. Early metal working processes from several millennia BC would have required plier-like devices to handle hot materials in the process of smithing or casting. Development from wooden to bronze pliers would have probably happened sometime prior to 3000 BC. Among the oldest illustrations of pliers are those showing the Greek god Hephaestus in his smithy. Today, pliers intended principally to be used for safely handling hot objects are usually called tongs. The number of different designs of pliers grew with the invention of the different objects which they were used to handle: horse shoes, fasteners, wire, pipes, electrical and electronic components. Design. The basic design of pliers has changed little since their origins, with the pair of "handles", the "pivot" (often formed by a rivet), and the "head" section with the gripping jaws or cutting edges forming the three elements. In distinction to a pair of scissors or shears, the plier's jaws always meet each other at one pivot angle. Pliers are an instrument that convert a power grip—the curling of the fingers into the palm of the hand—into a precision grip, directing the power of the hand's grip in a precise fashion on to the objects to be gripped. The handles are long relative to the shorter nose of the pliers. The two arms thus act as first class levers with a mechanical advantage, increasing the force applied by the hand's grip and concentrating it on the work piece. The materials used to make pliers consist mainly of steel alloys with additives such as vanadium or chromium, to improve alloy strength and prevent | A saw is a tool that uses a hard blade or wire with an abrasive edge to cut through softer materials. The cutting edge of a saw is either a serrated blade or an abrasive. A saw may be worked by hand, or powered by steam, water, electric or other power. In a modern serrated saw, each tooth is bent to a precise angle called its "set". The set of the teeth is determined by the kind of cut the saw is intended to make. For example, a "rip saw" has a tooth set that is similar to the angle used on a chisel. The idea is to have the teeth rip or tear the material apart. Some teeth are usually splayed slightly to each side the blade, so that the cut width (kerf) is wider than the blade itself and the blade does not bind in the cut. The kerf of the blade is adjusted with a tool called a saw tooth setter. An abrasive saw uses an abrasive disc or band for cutting, rather than a serrated blade. According to Chinese tradition, the saw was invented by Lu Ban. In Greek mythology, Talos, the nephew of Daedalos, invented the saw. In fact, saws date back to prehistory, and likely evolved from Neolithic tools or bone tools. The early ancestors of man, in the Pleistocene era, likely first used a jaw bone of 5 bovid animals as a saw. Types of saw blades and the cuts they make. Blade teeth are of two general types: Tool steel or carbide. Carbide is harder and holds a sharp edge much longer. Materials used for saws. There are several materials used in saws, with each of its own specifications. |