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Disposable Razor
A razor is a bladed tool primarily used in the removal of body hair through the act of shaving. Kinds of razors include straight razors, safety razors, disposable razors, and electric razors. While the razor has been in existence since before the Bronze Age (the oldest razor-like object has been dated to 18,000 BC), the most common types of razors currently used are the safety razor and the electric razor. History Razors have been identified from many Bronze Age cultures. These were made of bronze or obsidian and were generally oval-shaped, with a small tang protruding from one of the short ends.Warwickshire County Council: New Prehistoric Archaeology Objects "Even further away in time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Grooming
Grooming (also called preening) is the art and practice of cleaning and maintaining parts of the body. It is a species-typical behavior. In animals Individual animals regularly clean themselves and put their fur, feathers or other skin coverings in good order. This activity is known as personal grooming, a form of hygiene. Extracting foreign objects such as insects, leaves, dirt, twigs and parasites is a form of grooming. Among animals, birds spend considerable time preening their feathers. This is done to remove ectoparasites, keep the feathers in good aerodynamic condition, and waterproof them. To do that, they use the preen oil secreted by the uropygial gland, the dust of down feathers, or other means such as dust-bathing or anting. During oil spills, animal conservationists that rescue penguins sometimes dress them in knitted sweaters to stop them from preening and thereby ingesting the mineral oil, which is poisonous. Monkeys may also pick out nits from their fur o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tang (tools)
A tang or shank is the back portion of the blade component of a tool where it extends into stock material or connects to a handle – as on a knife, sword, spear, arrowhead, chisel, file, coulter, pike, scythe, screwdriver, etc. One can classify various tang designs by their appearance, by the manner in which they attach to a handle, and by their length in relation to the handle. ''Nakago'' is the term in Japanese, used especially when referring to the tang of the katana or the wakizashi. Full vs partial tang A full tang extends the full length of the grip-portion of a handle, versus a ''partial'' tang which does not. A full tang may or may not be as wide as the handle itself, but will still run the full length of the handle. There are a wide variety of full and partial tang designs. In perhaps the most common design in full tang knives, the handle is cut in the shape of the tang and handle scales are then fastened to the tang by means of pins, screws, bolts, metal tubing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Crucible Steel
Crucible steel is steel made by melting pig iron (cast iron), iron, and sometimes steel, often along with sand, glass, ashes, and other fluxes, in a crucible. In ancient times steel and iron were impossible to melt using charcoal or coal fires, which could not produce temperatures high enough. However, pig iron, having a higher carbon content and thus a lower melting point, could be melted, and by soaking wrought iron or steel in the liquid pig-iron for a long time, the carbon content of the pig iron could be reduced as it slowly diffused into the iron, turning both into steel. Crucible steel of this type was produced in South and Central Asia during the medieval era. This generally produced a very hard steel, but also a composite steel that was inhomogeneous, consisting of a very high-carbon steel (formerly the pig-iron) and a lower-carbon steel (formerly the wrought iron). This often resulted in an intricate pattern when the steel was forged, filed or polished, with possibly t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. Measuring hardness There are three main types of hardness measurements: ''scratch' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
