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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 thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of 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 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 * The realisation of these units of measurement in practice * Traceabi ... [...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 Energy. Tasks Together with NIST in the USA and the 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 (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 as well as PTB’s responsibilities have been combined in this Act. Previously, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Verein Deutscher Ingenieure
Verein Deutscher Ingenieure (VDI) (English: Association of German Engineers) is an organization of over 150,000 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 Dampfkesselübe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the States of Germany, German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the List of cities in Germany by population, third-largest city in Germany, after Berlin and Hamburg, and thus the largest which does not constitute its own state, as well as the List of cities in the European Union by population within city limits, 11th-largest city in the European Union. The Munich Metropolitan Region, city's metropolitan region is home to 6 million people. Straddling the banks of the River Isar (a tributary of the Danube) north of the Northern Limestone Alps, Bavarian Alps, Munich is the seat of the Bavarian Regierungsbezirk, administrative region of Upper Bavaria, while being the population density, most densely populated municipality in Germany (4,500 people per km2). Munich is the second-largest city in the Bavarian dialects, Bavarian dialect area, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlin
Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constituent states, Berlin is surrounded by the State of Brandenburg and contiguous with Potsdam, Brandenburg's capital. Berlin's urban area, which has a population of around 4.5 million, is the second most populous urban area in Germany after the Ruhr. The Berlin-Brandenburg capital region has around 6.2 million inhabitants and is Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the Spree, which flows into the Havel (a tributary of the Elbe) in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree, Havel and Dahme, the largest of which is Lake Müggelsee. Due to its l ... [...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 a male thread (e.g. on a bolt) will pass through easily to create a well-located connection to an internally threaded component (e.g. a nut) on the other side. That is, 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 its majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thury Thread
Thury may refer to: People *Pierre de Thury ( -1410), said the cardinal Maillezais, a French cardinal of the Avignon Obedience, see Council of Pisa *György Thury (1519-1571), a Hungarian nobleman ( hu) *Louis-Pierre Thury (died in 1699), French missionary priest in Acadia *César-François Cassini de Thury (1714-1784), French geographer *Louis-Étienne Héricart de Thury (1776–1854), French scientist and politician *René Thury (1860-1938), a Swiss engineer Toponyms France *Thury, Côte-d'Or, in the Côte-d'Or (département) *Thury, Yonne, in the Yonne (département) *Thury-en-Valois, in the Oise (département) *Thury-Harcourt, in the Calvados (département) *Thury-sous-Clermont Thury-sous-Clermont (, literally ''Thury under Clermont'') is a commune in the Oise department in northern France. See also * Communes of the Oise department The following is a list of the 679 communes of the Oise department of France. The ..., in the Oise (département) * La Villeneuve-sous- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometer (device)
A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw widely used for accurate measurement of components in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and 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. Micrometers are also used in telescopes or microscopes to measure the apparent diameter of celestial bodies or microscopic objects. The micrometer used with a telescope was invented about 1638 by William Gascoigne, an English astronomer. History The word ''micrometer'' is a neoclassical coinage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American National Standards Institute
The American National Standards Institute (ANSI ) is a private non-profit 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 b ... [...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 may refer to: Objects * Thread (yarn), a kind of thin yarn used for sewing ** Thread (unit of measurement), a cotton yarn measure * Screw thread, a helical ridge on a cylindrical fastener Arts and entertainment * ''Thread'' (film), 2016 Greek film * ''Threads'' (1932 film), a film directed by G. B. Samuelson * ''Threads'' (1984 film), a 1984 BBC television movie about a nuclear attack * ''Threads'' (2017 film), a Norwegian-Canadian animated short film * "Threads" (''Stargate SG-1''), a 2005 Stargate SG-1 episode * "Thread", a poem by Patti Smith from ''Babel'' * Thread, a lethal spore in the Dragonriders of Pern universe * ''Phantom Thread'', 2017 American historical drama film * '' Project Runway: Threads'', a Project Runway spin-off with child contestants Music * ''Threads'' (Battlefield Band album), 1995 * ''Threads'' (David S. Ware album), 2003 * ''Threads'' (Now, Now album), 2012 * ''Threads'' (Temposhark album), 2010 * ''Threads'' (Sheryl Crow album), 2019 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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