|
Surface Feet Per Minute
Surface feet per minute (SFPM or SFM) is the combination of a physical quantity (''surface speed'') and an imperial and American customary unit (''feet per minute'' or ''FPM''). It is defined as the number of linear feet that a location on a rotating component travels in one minute. Its most common use is in the measurement of cutting speed (surface speed) in machining. It is a unit of velocity that describes how fast the cutting edge of the cutting tool travels. It correlates directly to the machinability of the workpiece material and the hardness of the cutting tool material. It relates to spindle speed via variables such as cutter diameter (for rotating cutters) or workpiece diameter (for lathe work). SFM is a combination of ''diameter'' and the ''velocity'' (RPM) of the material measured in feet-per-minute as the spindle of a milling machine or lathe A lathe () is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Quantity
A physical quantity is a physical property of a material or system that can be quantified by measurement. A physical quantity can be expressed as a ''value'', which is the algebraic multiplication of a ' Numerical value ' and a ' Unit '. For example, the physical quantity of mass can be quantified as '32.3 kg ', where '32.3' is the numerical value and 'kg' is the Unit. A physical quantity possesses at least two characteristics in common. # Numerical magnitude. # Units Symbols and nomenclature International recommendations for the use of symbols for quantities are set out in ISO/IEC 80000, the IUPAP red book and the IUPAC green book. For example, the recommended symbol for the physical quantity ''mass'' is ''m'', and the recommended symbol for the quantity ''electric charge'' is ''Q''. Subscripts and indices Subscripts are used for two reasons, to simply attach a name to the quantity or associate it with another quantity, or index a specific component (e.g., row or colum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spindle (tool)
In machine tools, a spindle is a rotating axis of the machine, which often has a shaft at its heart. The shaft itself is called a spindle, but also, in shop-floor practice, the word often is used metonymically to refer to the entire rotary unit, including not only the shaft itself, but its bearings and anything attached to it (chuck, etc.). A machine tool may have several spindles, such as the headstock and tailstock spindles on a bench lathe. The main spindle is usually the biggest one. References to "the spindle" without further qualification imply the main spindle. Some machine tools that specialize in high-volume mass production have a group of 4, 6, or even more main spindles. These are called multispindle machines. For example, gang drills and many screw machines are multispindle machines. Although a bench lathe has more than one spindle (counting the tailstock), it is not called a multispindle machine; it has one main spindle. Examples of spindles include * On a la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Units Of Velocity
Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (album), 1997 album by the Australian band Regurgitator * The Units, a synthpunk band Television * ''The Unit'', an American television series * '' The Unit: Idol Rebooting Project'', South Korean reality TV survival show Business * Stock keeping unit, a discrete inventory management construct * Strategic business unit, a profit center which focuses on product offering and market segment * Unit of account, a monetary unit of measurement * Unit coin, a small coin or medallion (usually military), bearing an organization's insignia or emblem * Work unit, the name given to a place of employment in the People's Republic of China Science and technology Science and medicine * Unit, a vessel or section of a chemical plant * Blood unit, a measurement ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machining
Machining is a process in which a material (often metal) is cut to a desired final shape and size by a controlled material-removal process. The processes that have this common theme are collectively called subtractive manufacturing, which utilizes machine tools, in contrast to ''additive manufacturing'' (3D printing), which uses controlled addition of material. Machining is a part of the manufacture of many metal products, but it can also be used on other materials such as wood, plastic, ceramic, and composite material. A person who specializes in machining is called a machinist. A room, building, or company where machining is done is called a machine shop. Much of modern-day machining is carried out by computer numerical control (CNC), in which computers are used to control the movement and operation of the mills, lathes, and other cutting machines. This increases efficiency, as the CNC machine runs unmanned therefore reducing labour costs for machine shops. History and ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speeds And Feeds
The phrase speeds and feeds or feeds and speeds refers to two separate velocities in machine tool practice, cutting speed and feed rate. They are often considered as a pair because of their combined effect on the cutting process. Each, however, can also be considered and analyzed in its own right. ''Cutting speed'' (also called ''surface speed'' or simply ''speed'') is the speed difference (relative velocity) between the cutting tool and the surface of the workpiece it is operating on. It is expressed in units of distance across the workpiece surface per unit of time, typically surface feet per minute (sfm) or meters per minute (m/min). ''Feed rate'' (also often styled as a solid compound, ''feedrate'', or called simply ''feed'') is the relative velocity at which the cutter is advanced along the workpiece; its vector is perpendicular to the vector of cutting speed. Feed rate units depend on the motion of the tool and workpiece; when the workpiece rotates (''e.g.'', in turning an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International System Of Units
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. Established and maintained by the General Conference on Weights and Measures (CGPM), it is the only system of measurement with an official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The SI comprises a coherent system of units of measurement starting with seven base units, which are the second (symbol s, the unit of time), metre (m, length), kilogram (kg, mass), ampere (A, electric current), kelvin (K, thermodynamic temperature), mole (mol, amount of substance), and candela (cd, luminous intensity). The system can accommodate coherent units for an unlimited number of additional quantities. These are called coherent derived units, which can always be represented as p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lathe
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, facing, and turning, with tools that are applied to the workpiece to create an object with symmetry about that axis. Lathes are used in woodturning, metalworking, metal spinning, thermal spraying, parts 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 solids of revolution, plane surfaces and screw threads or 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 varying workpiece lengths. Other work-holding methods include clamping the work about the axis of rotation using a chuck or col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milling Machine
Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying direction on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of different operations and machines, on scales from small individual parts to large, heavy-duty gang milling operations. It is one of the most commonly used processes for machining custom parts to precise tolerances. Milling can be done with a wide range of machine tools. The original class of machine tools for milling was the milling machine (often called a mill). After the advent of computer numerical control (CNC) in the 1960s, milling machines evolved into ''machining centers'': milling machines augmented by automatic tool changers, tool magazines or carousels, CNC capability, coolant systems, and enclosures. Milling centers are generally classified as vertical machining centers (VMCs) or horizontal machining centers (HMCs). The integra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionless unit equal to 1, which it refers to as a revolution, but does not define the revolution as a unit. It defines a unit of rotational frequency equal to s−1. The superseded standard ISO 80000-3:2006 did however state with reference to the unit name 'one', symbol '1', that "The special name revolution, symbol r, for this unit is widely used in specifications on rotating machines." The International System of Units (SI) does not recognize rpm as a unit, and defines the unit of frequency, Hz, as equal to s−1. :\begin 1~&\text &&=& 60~&\text \\ \frac~&\text &&=& 1~&\text \end A corresponding but distinct quantity for describing rotation is angular velocity, for which the SI unit is the ra ... [...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] |
Imperial Units
The imperial system of units, imperial system or imperial units (also known as British Imperial or Exchequer Standards of 1826) is the system of units first defined in the British Weights and Measures Act 1824 and continued to be developed through a series of Weights and Measures Acts and amendments. The imperial system developed from earlier English units as did the related but differing system of customary units of the United States. The imperial units replaced the Winchester Standards, which were in effect from 1588 to 1825. The system came into official use across the British Empire in 1826. By the late 20th century, most nations of the former empire had officially adopted the metric system as their main system of measurement, but imperial units are still used alongside metric units in the United Kingdom and in some other parts of the former empire, notably Canada. The modern UK legislation defining the imperial system of units is given in the Weights and Measures Act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.svg "Click for more on -> International System Of Units")
