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Raker (saw)
A crosscut saw (thwart saw) is any saw designed for cutting wood perpendicular to (across) the wood grain. Crosscut saws may be small or large, with small teeth close together for fine work like woodworking or large for coarse work like log bucking, and can be a hand tool or power tool. The cutting edge of each tooth is angled in an alternating pattern. This design allows each tooth to act like a knife edge and slice through the wood in contrast to a rip saw, which tears along the grain, acting like a miniature chisel. Some crosscut saws use special teeth, called ''rakers'', designed to clean out the cut strips of wood from the ''kerf''. Crosscut saws generally have smaller teeth than rip saws. Some saws, such as Japanese saws and those used by the ancient Egyptians, are designed to cut only on the pull stroke. Western saws, on the other hand, are designed to cut on the push stroke. Cross cut saws designed for log bucking and tree felling are designed to cut on the pull strok ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Saw
In woodworking and carpentry, hand saws, also known as "panel saws", are used to cut pieces of wood into different shapes. This is usually done in order to Woodworking joints, join the pieces together and carve a wooden object. They operate by having a series of sharp points, called teeth, of a substance that is harder than the wood being cut. Hand saws have been used for thousands of years. Egyptian hieroglyphs, Egyptian hieroglyphics exist depicting ancient woodworkers sawing boards into pieces, and ancient bow saws have been found in Japan. Cut patterns on ancient boards are occasionally observed to bear the unique cutting marks left by saw blades, particularly if the wood was not 'smoothed up' by some method. Twenty-four saws from eighteenth-century England are currently preserved.Olmert, Michael (1996). ''Milton's Teeth and Ovid's Umbrella: Curiouser & Curiouser Adventures in History'', p.178. Simon & Schuster, New York. . Materials for saw blades have varied over the ages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axe (tool)
An axe (; sometimes spelled ax in American English; American and British English spelling differences#Miscellaneous spelling differences, see spelling differences) is an implement that has been used for thousands of years to shape, split, and cut wood, to harvest timber, and as a weapon. The axe has many forms and specialised uses but generally consists of a head with a handle (also called "haft" or "helve"). Before the modern axe, the Stone Age, stone-age hand axe without a handle was used from 1.5 million years Before Present, BP. Hafted axes (those with a handle) date only from 6,000 BC. The earliest examples of handled axes have heads of stone with some form of wooden handle attached (hafting, hafted) in a method to suit the available materials and use. Axes made of copper, bronze, iron and steel appeared as these technologies developed. The axe is an example of a simple machine, as it is a type of Wedge (mechanical device), wedge, or dual inclined plane. This reduces t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wedge (mechanical Device)
A wedge is a triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. It functions by converting a force applied to its blunt end into forces perpendicular ( normal) to its inclined surfaces. The mechanical advantage of a wedge is given by the ratio of the length of its slope to its width..''McGraw-Hill Concise Encyclopedia of Science & Technology'', Third Ed., Sybil P. Parker, ed., McGraw-Hill, Inc., 1992, p. 2041. Although a short wedge with a wide angle may do a job faster, it requires more force than a long wedge with a narrow angle. The force is applied on a flat, broad surface. This energy is transported to the pointy, sharp end of the wedge, hence the force is transported. The wedge simply transports energy in the form of friction and collects it to the pointy end, consequently breaking the item. History Wedges have existed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Carbon Steel
Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: * no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium, tungsten, vanadium, zirconium, or any other element to be added to obtain a desired alloying effect; * the specified minimum for copper does not exceed 0.40%; * or the specified maximum for any of the following elements does not exceed: manganese 1.65%; silicon 0.60%; and copper 0.60%. As the carbon content percentage rises, steel has the ability to become harder and stronger through heat treating; however, it becomes less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point. The term may be used to reference steel that is not stainless steel; in this use carbon steel may include alloy steels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angeles National Forest
The Angeles National Forest (ANF) of the United States Forest Service is located in the San Gabriel Mountains and Sierra Pelona Mountains, primarily within Los Angeles County in Southern California. The ANF manages a majority of the San Gabriel Mountains National Monument. The national forest was established in 1908, incorporating the first San Bernardino National Forest and parts of the former Santa Barbara and San Gabriel National Forests. Angeles National Forest headquarters are located in Arcadia, California. Geography The Angeles National Forest covers a total of , protecting large areas of the San Gabriel Mountains and Sierra Pelona Mountains. It is located just north of the densely inhabited metropolitan area of Greater Los Angeles. While primarily within Los Angeles County, a small part extends eastward into southwestern San Bernardino County, in the Mount San Antonio ("Mount Baldy") area, and a tiny section also extends westward into northeastern Ventura Count ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Forest Service
The United States Forest Service (USFS) is an agency within the United States Department of Agriculture, U.S. Department of Agriculture. It administers the nation's 154 United States National Forest, national forests and 20 United States National Grassland, national grasslands covering of land. The major divisions of the agency are the Chief's Office, National Forest System, State and Private Forestry, Business Operations, as well as Research and Development. The agency manages about 25% of federal lands and is the sole major national land management agency not part of the United States Department of the Interior, U.S. Department of the Interior (which manages the National Park Service, the U.S. Fish and Wildlife Service and the Bureau of Land Management). History In 1876, Congress formed the office of Special Agent in the Department of Agriculture to assess the quality and conditions of forests in the United States. Franklin B. Hough was appointed the head of the office. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Forest
In the United States, national forest is a classification of protected and managed federal lands that are largely forest and woodland areas. They are owned collectively by the American people through the federal government and managed by the United States Forest Service, a division of the United States Department of Agriculture. The U.S. Forest Service is also a forestry research organization that provides financial assistance to the state and local forestry industry. There are 154 national forests in the United States. History The Land Revision Act of 1891, enacted during the presidency of Benjamin Harrison, allowed the president to set aside forest reserves on public lands. Harrison established 15 forest reserves containing more than 13 million acres of land. The bill was the result of concerted action by Los Angeles-area businessmen and property owners who were concerned by the harm being done to the watershed of the San Gabriel Mountains by ranchers and miners. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chainsaw
A chainsaw (or chain saw) is a portable handheld power saw, power saw that cuts with a set of teeth attached to a rotating chain driven along a guide bar. Modern chainsaws are typically gasoline or electric and are used in activities such as tree felling, limbing, Log bucking, bucking, pruning, cutting firebreaks in wildland fire suppression, harvesting of Wood fuel#Firewood, firewood, for use in Chainsaw carving, chainsaw art and chainsaw mills, for cutting concrete, and cutting ice. Precursors to modern chainsaws were first used in surgery, with patents for wood chainsaws beginning in the late 19th century. A chainsaw comprises an engine, a drive mechanism, a guide bar, a cutting chain, a tensioning mechanism, and safety features. Various safety practices and working techniques are used with chainsaws. History In surgery A "flexible saw", consisting of a fine serrated link chain held between two wooden handles, was pioneered in the late 18th century (–1785) by two Scot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvania
Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions of the United States. It borders Delaware to its southeast, Maryland to its south, West Virginia to its southwest, Ohio and the Ohio River to its west, Lake Erie and New York (state), New York to its north, the Delaware River and New Jersey to its east, and the Provinces and territories of Canada, Canadian province of Ontario to its northwest via Lake Erie. Pennsylvania's most populous city is Philadelphia. Pennsylvania was founded in 1681 through a royal land grant to William Penn, the son of William Penn (Royal Navy officer), the state's namesake. Before that, between 1638 and 1655, a southeast portion of the state was part of New Sweden, a Swedish Empire, Swedish colony. Established as a haven for religious and political tolerance, the B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Empire
The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of effective sole rule in 27 BC. The Western Roman Empire, western empire collapsed in 476 AD, but the Byzantine Empire, eastern empire lasted until the fall of Constantinople in 1453. By 100 BC, the city of Rome had expanded its rule from the Italian peninsula to most of the Mediterranean Sea, Mediterranean and beyond. However, it was severely destabilised by List of Roman civil wars and revolts, civil wars and political conflicts, which culminated in the Wars of Augustus, victory of Octavian over Mark Antony and Cleopatra at the Battle of Actium in 31 BC, and the subsequent conquest of the Ptolemaic Kingdom in Egypt. In 27 BC, the Roman Senate granted Octavian overarching military power () and the new title of ''Augustus (title), Augustus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
