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Löwenherz Thread
The Löwenherz thread is a largely obsolete metric thread form designed in the late nineteenth century and frequently applied in precision instruments. It is named after Dr. Leopold Löwenherz, who was the director of the metrology institute Physikalisch-Technische Bundesanstalt in Berlin. History In 1888, the Verein Deutscher Ingenieure introduced a thread form that specified threads for diameters from sizes 6 millimeters in diameter to 40 millimeters in diameter. In 1892, at the Congress for Introduction of Standardized Threads for Fixing Screws in Fine Mechanics in Munich, it was decided that the thread form would be truncated. The final form was announced in Berlin in 1894, where the series of thread forms was expanded to include sizes as small as 1 millimeter in diameter. Description The Löwenherz thread form is unique in having a thread pitch angle of 53°8′ (53.1333°), which is a smaller angle than the ISO metric thread form but a larger angle than the Thury threa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of Unit of measurement, units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the ''International Bureau of Weights and Measures, Bureau International des Poids et Mesures'' (BIPM) was established by the Metre Convention. This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960. Metrology is divided into three basic overlapping activities: * The definition of units of measurement * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physikalisch-Technische Bundesanstalt
The Physikalisch-Technische Bundesanstalt (PTB) is the national metrology institute of the Federal Republic of Germany, with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under federal government control, without legal capacity, under the auspices of the Federal Ministry for Economic Affairs and Climate Action. Tasks Together with NIST in the USA and the National Physical Laboratory (United Kingdom), NPL in Great Britain, PTB ranks among the leading metrology institutes in the world. As the National Metrology Institute of Germany, PTB is Germany's highest and only authority in terms of correct and reliable measurements. The Units and Time Act Bundesgesetzblatt (Germany), Bundesgesetzblatt (Federal Law Gazette), volume 2008, part I, No. 28, p. 1185 ff., 11 July 2008] assigns all tasks which are related with the realization and dissemination of the units to PTB. All legally relevant aspects regarding the units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verein Deutscher Ingenieure
Verein Deutscher Ingenieure (VDI) (English: Association of German Engineers) is an organization of about 135,000 engineers and natural scientists. More than 12,000 honorary experts process the latest technical findings each year to promote the technology location. Established in 1856, it is the largest engineering association in Western Europe. Its role in Germany is comparable to that of the American Society of Civil Engineers (ASCE) in the United States or Engineers Australia (EA) in Australia, but includes broader field work. It is not a union, but promotes the advancement of technology and represents the interests of engineers and engineering businesses in Germany. History The organization was founded on May 12, 1856 by fellow researchers from the Academic Fraternity Hütte, in the small town of Alexisbad, with the first journal officially being released to the public in 1857. In 1866 the VDI helped establish the predecessor of Technischer Überwachungsverein, the Dampfkes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich
Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is not a state of its own. It ranks as the 11th-largest city in the European Union. The metropolitan area has around 3 million inhabitants, and the broader Munich Metropolitan Region is home to about 6.2 million people. It is the List of EU metropolitan regions by GDP#2021 ranking of top four German metropolitan regions, third largest metropolitan region by GDP in the European Union. Munich is located on the river Isar north of the Alps. It is the seat of the Upper Bavaria, Upper Bavarian administrative region. With 4,500 people per km2, Munich is Germany's most densely populated municipality. It is also the second-largest city in the Bavarian language, Bavarian dialect area after Vienna. The first record of Munich dates to 1158. The city ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population within city limits, highest population within its city limits of any city in the European Union. The city is also one of the states of Germany, being the List of German states by area, third smallest state in the country by area. Berlin is surrounded by the state of Brandenburg, and Brandenburg's capital Potsdam is nearby. The urban area of Berlin has a population of over 4.6 million and is therefore the most populous urban area in Germany. The Berlin/Brandenburg Metropolitan Region, Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's second-largest metropolitan region after the Rhine-Ruhr region, as well as the List of EU metropolitan areas by GDP, fifth-biggest metropolitan region by GDP in the European Union. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ISO Metric Screw Thread
The ISO metric screw thread is the most commonly used type of general-purpose screw thread worldwide. They were one of the first international standards agreed when the International Organization for Standardization (ISO) was set up in 1947. The "M" designation for metric screws indicates the nominal outer diameter of the screw thread, in millimetres. This is also referred to as the "major" diameter in the information below. It indicates the diameter of smooth-walled hole that an externally threaded component (e.g. on a bolt) will pass through easily to connect to an internally threaded component (e.g. a nut) on the other side. For example, an M6 screw has a nominal outer diameter of 6 millimetres and will therefore be a well-located, co-axial fit in a hole drilled to 6 mm diameter. Basic profile The design principles of ISO general-purpose metric screw threads ("M" series threads) are defined in international standard ISO 68-1. Each thread is characterized by it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thury Thread
The Swiss-designed Thury screw thread (alternatively called the Filière Suisse, FS, screw thread) is a metric thread standard that was developed in the late nineteenth century for screws used in scientific and horological instruments. The thread is named after Marc Thury, an engineer and professor at the University of Geneva who contributed heavily to the standard's development. History Development of the Thury thread began in 1876, when the Horological Section of Geneva Society of Arts appointed a committee to look into the requirements for a uniform thread standard for use in Horological arts in Switzerland. Professor Thury began his studies by collecting and measuring samples of screws made by nine independent screw and screw tackle manufacturers in Switzerland. The Thury thread form was developed in 1878, thirty-seven years after the British Standard Whitworth thread form was designed in England and fourteen years after the United States Standard thread was presented in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometer (device)
A micrometer, sometimes known as a micrometer screw gauge (MSG), is a device incorporating a calibrated screw for Accuracy and precision, accurate measurement of the size of components. It widely used in mechanical engineering, machining, metrology as well as most mechanical trades, along with other dimensional instruments such as Caliper#Dial caliper, dial, Caliper#Vernier caliper, vernier, and Caliper#Digital caliper, digital calipers. Micrometers are usually, but not always, in the form of calipers (opposing ends joined by a frame). The spindle is a very accurately machined screw and the object to be measured is placed between the spindle and the anvil. The spindle is moved by turning the ratchet knob or thimble until the object to be measured is lightly touched by both the spindle and the anvil. History The word ''micrometer'' is a classical compound, neoclassical coinage from and . According to the Webster's Dictionary#Merriam-Webster Collegiate Dictionary, ''Merriam-Web ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American National Standards Institute
The American National Standards Institute (ANSI ) is a private nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. ANSI accredits standards that are developed by representatives of other standards organizations, government agencies, consumer groups, companies, and others. These standards ensure that the characteristics and performance of products are consistent, that people use the same definitions and terms, and that products are tested the same way. ANSI also accredits organizations that carry out product or personnel certification in accordance with requirements defined in international standards. The organization's headquarters are in Washington, D.C. ANSI's operations office is located in New York City. The ANSI annual operating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Association Screw Threads
British Association screw threads, or BA screw threads, are a set of small screw threads, the largest being 0BA at 6 mm diameter. They were, and to some extent still are, used for miniature instruments and modelling. They are unusual in that they were probably the most "scientific" design of screw, starting with 0BA at 6.0 mm diameter and 1.0 mm pitch and progressing in a geometric sequence where each larger number was 0.9 times the pitch of the last size. They then rounded to 2 significant figures in metric and then converting to inches and rounding to the thousandth of an inch. This anticipated worldwide metrication by about a century. The design was first proposed by the British Association in 1884 with a thread angle and depth based on the Swiss Thury thread, it was adopted by the Association in 1903. The Thury thread was different in that it went both positive and negative all the way up to a size of −20 which was 75.2 mm diameter by 8.23 mm pitch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread Standards
Thread(s) may refer to: Objects * Thread (yarn) ** Thread (unit of measurement), a cotton yarn measure * Screw thread, a helical ridge on a cylindrical fastener * Thread, an individual strand of spider silk Arts and entertainment * ''Thread'' (film), 2016 Greek film * ''Threads'' (1932 film), directed by G. B. Samuelson * ''Threads'' (1984 film), apocalyptic nuclear war drama film * ''Threads'' (2017 film), animated short film * "Threads" (''Stargate SG-1''), a Stargate SG-1 episode * "Thread", a poem by Patti Smith from '' Babel'' * Thread, a lethal spore in the Dragonriders of Pern universe * ''The Threads '', Indian National Film Award for Best Non-Feature Animation Film winner * '' Project Runway: Threads'', spinoff television series with child contestants Music * ''Thread'' (album), by rock band Red Sun Rising * ''Threads'' (Battlefield Band album) * ''Threads'' (David S. Ware album) * ''Threads'' (Now, Now album) * ''Threads'' (Temposhark album) * ''Threads'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
