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Grinding (abrasive Cutting)
Grinding is a type of abrasive machining process which uses a grinding wheel as cutting tool. A wide variety of machines are used for grinding, best classified as portable or stationary: * Portable power tools such as angle grinders, die grinders and cut-off saws * Stationary power tools such as bench grinders and cut-off saws * Stationary hydro- or hand-powered sharpening stones Milling practice is a large and diverse area of manufacturing and toolmaking. It can produce very fine finishes and very accurate dimensions; yet in mass production contexts, it can also rough out large volumes of metal quite rapidly. It is usually better suited to the machining of very hard materials than is "regular" machining (that is, cutting larger chips with cutting tools such as tool bits or milling cutters), and until recent decades it was the only practical way to machine such materials as hardened steels. Compared to "regular" machining, it is usually better suited to taking very ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thousandth Of An Inch
A thousandth of an inch is a derived unit of length in a system of units using inches. Equal to of an inch, a thousandth is commonly called a thou (used for both singular and plural) or, particularly in North America, a mil (plural mils). The words are shortened forms of the English and Latin words for "thousand" ( in Latin). In international engineering contexts, confusion can arise because ''mil'' is a formal unit name in North America but ''mil'' or ''mill'' is also a common colloquial clipped form of millimetre. The units are considerably different: a millimetre is approximately 39 mils. Contexts of use The thou, or mil, is most commonly used in engineering and manufacturing in non-metric countries. For example, in specifying: * The thickness of items such as paper, film, foil, wires, paint coatings, latex gloves, plastic sheeting, and fibers ** For example, most plastic ID cards are about in thickness. ** Card stock thickness in the United States, where mils are also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chuck (engineering)
A chuck is a specialized type of clamp (tool), clamp used to hold an object with rotational symmetry, radial symmetry, especially a cylinder (geometry), cylinder. In a drill, a Milling (machining), mill and a transmission (mechanics), transmission, a chuck holds the rotating tool bit, tool; in a lathe, it holds the rotating workpiece. Chucks commonly use jaws to hold the tool or workpiece. The jaws are typically arranged in a radially symmetrical pattern like the points of a star (polygon), star. Jawed chucks may require a Wrench#Other types of keys, wrench-like device called a ''chuck key'' to be tightened or loosened, but other jawed chucks may be tightened or loosened by hand force alone, offering convenience at the expense of gripping force. Chucks on some lathes have jaws that move independently, allowing them to hold irregularly shaped objects. More complex designs might include specially shaped jaws, greater numbers of jaws, or quick-release mechanisms. Instead of jaws, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Finish
Surface finish, also known as surface texture or surface topography, is the nature of a interface (matter), surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a surface from the perfectly Flat space, flat ideal (a true plane (geometry), plane). Surface texture is one of the important factors that control friction and transfer layer formation during sliding. Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions. Surface textures can be isotropy, isotropic or anisotropy, anisotropic. Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture. Each manufacturing process (such as the many kinds of machining) produces a surface texture. The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylindrical Grinder
The cylindrical grinder is a type of grinding machine used to shape the outside of an object. The cylindrical grinder can work on a variety of shapes, however the object must have a central axis of rotation. This includes but is not limited to such shapes as a Cylinder (geometry), cylinder, an ellipse, a Cam (mechanism), cam, or a crankshaft.Lewis, Kenneth. ''The Grinding Wheel''. 2nd. Cleveland: Judson Company, 1959. 104-141. Cylindrical grinding is defined as having four essential actions: #The work (object) must be constantly rotating #The grinding wheel must be constantly rotating #The grinding wheel is fed towards and away from the work #Either the work or the grinding wheel is transversed with respect to the other. While the majority of cylindrical grinders employ all four movements, there are grinders that only employ three of the four actions. History The origins of the cylindrical grinder, as with all other modern machine tools, stem from the experimentation and inventi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lathe Dog
A lathe () is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, Deformation (engineering), deformation, facing (machining), facing, Threading (manufacturing), threading and turning, with tools that are applied to the workpiece to create an object with rotational symmetry, symmetry about that axis. Lathes are used in woodturning, metalworking, metal spinning, thermal spraying, reclamation, and glass-working. Lathes can be used to shape pottery, the best-known design being the Potter's wheel. Most suitably equipped metalworking lathes can also be used to produce most Solid of revolution, solids of revolution, plane surfaces and screw threads or helix, helices. Ornamental lathes can produce three-dimensional solids of incredible complexity. The workpiece is usually held in place by either one or two ''centers'', at least one of which can typically be moved horizontally to accommodate var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lathe Center
A lathe center, often shortened to center, is a tool that has been ground to a point to accurately position a workpiece on an axis. They usually have an included angle of 60°, but in heavy machining situations an angle of 75° is used. The primary use of a center is to ensure concentric work is produced; this allows the workpiece to be transferred between machining (or inspection) operations without any loss of accuracy. A part may be ''turned'' in a lathe, sent off for hardening and tempering and then ground ''between centers'' in a cylindrical grinder. The preservation of concentricity between the turning and grinding operations is crucial for quality work. When turning between centers, a steady rest can be used to support longer workpieces where the cutting forces would deflect the work excessively, reducing the finish and accuracy of the workpiece, or creating a hazardous situation. A lathe center has applications anywhere that a ''centered'' workpiece may be used; this i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machinists Grinding Workpieces On A Bench Grinder
A machinist is a tradesperson or trained professional who operates machine tools, and has the ability to set up tools such as milling machines, grinders, lathes, and drilling machines. A competent machinist will generally have a strong mechanical aptitude, the ability to correctly use precision measuring instruments and to interpret blueprints, and a working knowledge of the proper parameters required for successfully utilizing the various tools commonly used in machining operations. CNC (computer numerical control) comprises one of the most recent advances in manufacturing, in which a machinist uses specialized software to generate programmatic instructions (most commonly G-code) which are in turn interpreted by the machine to make components for a wide variety of industries. CNC programming is a skilled position which requires knowledge of math, speeds and feeds, machine tooling, work holding, and the different ways various materials react to stress and heat in the machining p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erwin Junker
Erwin Junker (15 April 1930 – 13 July 2024) was a German manufacturer who was the owner and founder of the Junker Group. Early life and education Erwin Junker was born on 15 April 1930, in the Black Forest town of Nordrach, near Offenburg, Germany, to saw mill owners Zäzilia and Ludwig Junker as the oldest of five children. After attending the elementary school in the Kolonie district, he worked for his parents’ company for three years. However, instead of taking over his parents’ business, as was the tradition, Erwin Junker opted for a career in mechanical engineering. In 1947, he started an apprenticeship with the Haas Company. After a year he switched to the Company Prototyp in Zell am Harmersbach, where he was working from 1948 to 1962. Starting out as an apprentice, he worked his way up to becoming an assistant mechanical engineer before continuing his education to receive his master craftsman degree. Subsequently, he moved to the mechanical engineering department, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Second
The second (symbol: s) is a unit of time derived from the division of the day first into 24 hours, then to 60 minutes, and finally to 60 seconds each (24 × 60 × 60 = 86400). The current and formal definition in the International System of Units (SI) is more precise: The second ..is defined by taking the fixed numerical value of the caesium frequency, Δ''ν''Cs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be when expressed in the unit Hz, which is equal to s−1. This current definition was adopted in 1967 when it became feasible to define the second based on fundamental properties of nature with caesium clocks. As the speed of Earth's rotation varies and is slowing ever so slightly, a leap second is added at irregular intervals to civil time to keep clocks in sync with Earth's rotation. The definition that is based on of a rotation of the earth is still used by the Universal Time 1 (UT1) system. Etymology "Minute" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandpaper
upright=1.35, Sheets of sandpaper with different grit sizes (40 (coarse), 80, 150, 240, 600 (fine)) Sandpaper, also known as coated abrasive or emery paper, is a type of material that consists of sheets of paper or cloth with an abrasive substance glued to one face. In the modern manufacture of these products, sand and glass have been replaced by other abrasives such as aluminium oxide or silicon carbide. It is common to use the name of the abrasive when describing the paper, e.g. "aluminium oxide paper", or "silicon carbide paper". There are many varieties of sandpaper, with variations in the paper or backing, the material used for the grit, grit size, and the bond. Sandpaper is produced in a range of grit sizes and is used to remove material from surfaces, whether to make them smoother (for example, in painting and wood finishing), to remove a layer of material (such as old paint), or sometimes to make the surface rougher (for example, as a preparation for gluing). The grit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
