Inch is a measure of length in centimeters. Inches in the designation of water and gas pipes

14.09.2018

Plan
Introduction
1 Different inches
1.1 Austria-Hungary
1.2 UK
1.3 Germany
1.4 Spain
1.5 Quebec
1.6 China
1.7 Mexico
1.8 Ostsee counties
1.9 Commonwealth, Poland
1.10 Rio de la Plata
1.11 US
1.12 France
1.13 Japan
1.14 Vidicon inch

2 inches in Russia
3 Designation
4 Origin
Bibliography

Introduction

Inch (from the Dutch. duim - thumb) - a unit of distance in some European non-metric systems of measures, usually equal to 1/12 or 1/10 ("decimal inch") of the foot of the corresponding country (in Russian and English systems of measures 1 inch \u003d 10 lines ("big line")). The word "inch" was introduced into Russian by Peter I at the very beginning of the 18th century. Today, an inch is most often understood as an English inch, equal to 2.54 cm.

1. Different inches

Austria-Hungary Vienna inch = 2.6340278 cm. UK

English inch or imperial inch(English) inch from lat. uncia- 1/12 part) since 1958 is equal to exactly 2.54 cm. Previously, it was converted to the metric system in a different way:

1819 - 1000000/393694 cm ≈ 2.5400438 cm;

1895 - 2.5399978 cm;

1922 - 2.5399956 cm;

1932 - 2.5399950 cm;

· 1947 - 2.5399931 cm.

In English units, 1 inch = 12 lines = 72 points = 1/12 foot = 1/36 yard.

1.3. Germany

· Bavaria: 2.43216 cm or 2.918592 cm ("decimal inch");

· Baden: 3 cm (1810);

· Prussia: 2.61545 cm (1755), 3.76625 cm ("decimal inch", 1816);

· Confederation of the Rhine: 2.61541 cm;

· Saxony: 2.36 cm.

Spain 1 pulgada = 2.32166 cm. Quebec French inch was used, but since 1985 the value has changed: 2.707005 cm. China 1 cun = 1/30 m ≈ 3.33333 cm. Mexico

1 pulgada = 2.3278 cm.

1.8. Ostsee provinces

Along with Rhine inches (see above, in the section on Germany), the following were used:

· Courland inch≈ 3.36 cm;

· Riga inch≈ 2.24 cm;

· revel inch≈ 2.6715 cm.

1.9. Commonwealth, Poland

· Old Polish or crown inch(until 1819) ≈ 2.48 cm;

· novopol inch(1819-1849) = exactly 2.4 cm;

· Wroclaw (Breslav , Silesian) inch= 2.742 cm;

· old Lithuanian inch≈ 2.7076 cm.

Rio de la Plata1 pulgada ≈ 2.547 cm. USA

As in Great Britain, since 1958 the American inch has been equal to 2.54 cm. Previously (since 1866) it was equal to 2.540000508 cm (more precisely, 10000/3937 cm); sometimes this old meaning is used today under the name survey inch .

The caliber of small arms in the United States is usually measured in hundredths of an inch, (in the UK it is traditionally in thousandths). For example, the famous 45 gauge is 0.45 inches (or 11.43 mm); 30th is 0.30 inches (or 7.62 mm); 50th is 0.50 inch (or 12.7 mm), etc.

1.12. France

French inch(fr. pouce- thumb), also known by the names Parisian inch and royal inch, was equal to 75000/27706 cm, that is, approximately 2.706995 cm. In the old Parisian system of measures, 1 inch \u003d 12 lines \u003d 144 points \u003d 1/12 feet \u003d 72/3161 cubits \u003d 1/72 toise.

Japan 1 sun = 1/33 m ≈ 3.0 cm Widicon inch

Equals 2/3 of an ordinary inch or 16.93mm. Most often it is used to measure the diagonal of the matrix of digital cameras.

For example, 1 / 2.7 "is 1 divided by 2.7 and multiplied by 16.93mm i.e. 6.27mm

2. Inches in Russia

In Russia, the English inch was the most famous (including under the name from the original language: insh(outdated), inch(obsolete, as well as modern jargon) and French inch; the first was more often used in science and technology, the second - in typography. According to the old Russian system of measures: 1 inch (equal to English) \u003d 10 lines \u003d 100 points \u003d 4/7 vershoks \u003d 1/12 feet (equal to English) \u003d 1/28 arshins \u003d 1/84 sazhens \u003d 1/42,000 versts, however in everyday life, not feet and inches were used, but proportionate to them arshins (= 7/3 feet) and vershoks (= 7/4 inches). In parallel with the definition of the Russian inch through English at the beginning of the 20th century, there was (also legalized) its metric expression, according to which the Russian inch is exactly 2.54 cm (it is not clear, however, how this was consistent with a different metric expression for the English inch of the same times).

After the transition of the USSR to the metric system, inches as such were practically forgotten and were used to a limited extent: in the mains of water supply and gas, the inch calculation (using integer fractions of an inch) remained for pipe diameters; some calibers of artillery were unofficially expressed (the most famous are “three-inchers” - guns of 76.2 mm caliber), small arms (“three-rulers” - 7.62 mm), the length of nails, the thickness of boards and the size of some other objects, although the actual values \u200b\u200bof the sizes of various technical products quite often in inches (or other units of the old system) were expressed in rounder numbers than in the metric system.

When copying foreign technology, dimensions originally expressed in inches were often converted to the metric system not exactly, but at the rate of 2.5 cm per inch, which often subsequently created problems with the compatibility of nodes of different origin.

In recent years, under the influence of American technology and technical terminology, inches are used much more often in Russian. In particular, they express the size of various computer parts, assemblies and accessories: floppy disks, hard drives, displays, etc. The resolution is measured in dots per inch (dpi) and lines per inch (lpi). various devices graphic I/O. The screen diagonal of household television broadcast receivers, measured in centimeters in Soviet times, is now often indicated in inches. Diameter rims cars are also traditionally measured in inches (at the same time, tire dimensions and fastener parameters are in the metric system)

3. Designation

In modern Russian, there is no generally accepted letter abbreviation for inches (before the transition to the metric system, “dm” was used, but now decimeters are denoted this way). Most often, the English designation is copied: the same double stroke as in the designation of arc seconds (″ - U + 2033), placed without a space after numerical value, for example: 3″ (3 inches). In English-speaking countries, the abbreviation "in" is also used (from the English. inch- inch): "3 in".

4. Origin

It is generally believed that the inch was originally defined as the length of the top joint of the thumb. According to other legends, an inch was defined as 1/36 of a yard, which, in turn, was set as the distance between the tip of the nose and the thumb of the outstretched hand of King Henry I of England (there is a version that a yard was his sword). Another legend connects the definition of an inch with the length of three barley grains taken out of the middle part of the ear and placed one to the other with their ends. In English life, and now the measure is used barley grain equal to one third of an inch. It is important to note here that it is correct to designate inches as whole numbers and ordinary, and not decimal fractions.

Bibliography:

1. Steel water and gas pipes GOST 3262-75

2. Metrological parameters of pipes according to GOST 3262-75

3. Widely used diameters and correspondence of the conditional passage (in fractions of inches) to the nominal size (in mm): 1/8 inch - 6 mm; 1/4 inch - 8 mm; 3/8 inch - 10 mm; 1/2 - 15 mm; 3/4 - 20 mm; one inch - 25 mm; an inch and a quarter - 32 mm; one and a half inches - 40 mm; two inches - 50 mm; two and a half inches - 65 mm; 4 inches - 100 mm.

Width of an adult thumb. Word " inch”appeared in Russia thanks to Peter I. It happened at the beginning of the 18th century. In our current understanding, the concept inch” in most cases is associated with a value equal to 2.54 centimeters.

Russian inches.

The most widespread in our country are the values \u200b\u200bof English and French inches. They were most often used, one in science and technology, the other in typography. During the time of Peter the Great in Russia, the arshin (1 arshin = 71.12 centimeters) and the vershok (1 vershok = 4.44500 centimeters) were mainly used to measure distances. Together with the definition of Russian inches in Russia of the XX century there was its legalized metric value, according to which the Russian inch equated to 2.54 centimeters.

With the advent of the Soviet era inches were practically forgotten and were used to a limited extent - in the mains of water supply and gas, among the military (in artillery inches some calibers were expressed), in the length of the nails, the thickness of the boards and other areas of science and technology.

When copying foreign technologies, the dimensions expressed in inches, were often converted to the metric system, but not exactly, but based on the calculation of 2.50 centimeters, which often, later, led to discrepancies in the compatibility of various nodes.

Nowadays, with the advent of a large number foreign machinery and technology concept inches occurs quite often. An example is the area computer technology- sizes of floppy disks, hard drives and other components of computer components are traditionally marked in inches.

Inches when marking pipes.

The traditional designation of the diameters of water and gas pipelines pipes in inches does not express directly either internal or outside diameter s pipes. This designation is closer to the conditional passage designation pipeline elements that can be expressed as Anglo-American inch and in the metric European system. However, there are no formulas for translating pipe inches» in order to find out the actual external or inner diameter pipes. The value of the nominal passage in the metric system is also weakly related to the geometric internal pipe diameter. For an unambiguous comparison of inch values with metric ones, it is necessary to use reference literature and regulatory documentation.

GOST 3262-75 establishes specifications on the steel and gas pipelines pipes applied to water pipelines and gas pipelines. But there is no correlation between inch and metric standards. To normalize compliance with the standards for cutting pipe threads, you can use GOST 6357-81.

In the table, based on the above-mentioned state standards, approximate figures for correlating inch standards with metric ones are given.

Thread size designation	Nominal pipe diameter	Outside diameter external thread(pipes), mm	Pipe outer diameter, mm
1/8	6	9,728	10,2
1/4	8	13,157	13,5
8/8	10	16,662	17,0
1/2	15	20,955	21,3
3/4	20	26,441	26,8
1	25	33,249	33,5
1 1/4	32	41,910	42,3
1 1/2	40	47,803	48,0
2	50	59,614	60,0
2 1/2	65	75,184	75,5
3	80	87,884	88,5
3 1/2	90	100,330	101,3
4	100	113,030	114,0
5	125	138,430	140,0
6	150	163,830	165,0

Table 1. Conversion of inch values to metric.

In modern Russian there is no generally accepted letter designation for inches. Most often, the English designation ("") is copied - the two upper strokes following the magnitude digit. In English-speaking countries, the abbreviation "in" is usually used (from English inch - inch).

Origin of inch.

It is believed that inch was originally defined as the width of the thumb. According to other legends inch was defined as 1/36 of the core, which, in turn, was defined as the distance between the tip of the nose and the thumb of the outstretched hand of King Henry I of England. Another legend connects the definitions inches with the length of three dry barley grains, stretched out from the middle part of the ear and attached one to the other with their ends, which was determined by King Edward I. Until now, in English life, the measure “barley grain”, equal to one third inches. It should also be noted that it is more correct to designate inch whole number and ordinary and not decimal fractions.

It is generally believed that the inch was originally defined as the width of the thumb. According to other legends, the inch was defined as 1 ⁄ 36 part of the yard, which, in turn, was set as the distance between the tip of the nose and the thumb of the outstretched hand of King Henry I of England (there is a version that his sword was a yard long). Another legend connects the definition of an inch (“legal inch”) with the length of three dry barley grains taken out of the middle part of the ear and put one to the other with their ends, which was determined by an act of King Edward I. In English life, and now the measure "barley grain" is used (eng. barleycorn) equal to one third of an inch. It is important to note here that inches are usually denoted by whole numbers and ordinary fractions(with denominators 2, 4, 8, 16), not decimals.

In Russia, English inches were the most famous (including under the name from the original language: insh(outdated), inch(obsolete, as well as modern jargon) and French inch; the former was used more often in science and technology, the latter in typography. According to the old Russian system of measures: 1 inch (equal to English) \u003d 10 lines \u003d 100 points \u003d 4/7 inches \u003d 1 ⁄ 12 foot (equal to English) = 1 ⁄ 28 arshin = 1 ⁄ 84 fathoms = 1 ⁄ 42 000 versts, however, in everyday life, not feet and inches were used, but proportionate arshins (= 7 ⁄ 3 feet) and vershoks (= 7 ⁄ 4 inches). In parallel with the definition of the Russian inch through English at the beginning of the 20th century, there was a (also legalized) ratio of the inch to metric units of length: 1 inch = 25.39954 mm.

Germany

Bavaria: 2.43216 cm or 2.918592 cm ("decimal inch");
Baden: 3 cm ();
Prussia: 2.61545 cm (), 3.76625 cm ("decimal inch", );
Confederation of the Rhine: 2.61541 cm;
Saxony: 2.36 cm.

Spain

The units of the Didot typometric system, adopted in Russian typographical business, are based on divisions of the French inch.

Japan

1 sun = 1 ⁄ 33 m ≈ 3.03 cm

In engineering [ | ]

In recent years, under the influence of American technology and technical terminology, inches are used much more often in Russian. In particular, they express the size of various computer parts, assemblies and accessories: floppy disks, disks, TV screens, displays (monitor), etc. In dots per inch (dpi) and lines per inch (lpi), the resolution of various devices is measured graphic I/O. The screen diagonal of household television broadcast receivers, measured in centimeters in Soviet times, is now often indicated in inches.

In modern typography, in addition to French, the English inch is also used, especially in computers. Font sizes are measured in points, 72ths of an inch.

Vidicon inch[ | ]

Dimensions of camera matrices in inches

Equals ⅔ of an ordinary inch or approximately 16.93 mm [ ] . Most often it is used to measure the diagonal of the matrix of digital cameras.

For example, 1 / 2.7 "is a unit divided by 2.7 and multiplied by 16.93 mm, that is, 6.27 mm.

Pipe diameter [ | ]

The traditional designation of the diameters of water and gas pipes in inches does not directly express either the outer or inner diameters of the pipes. Such a designation is closer to the designation of the nominal diameter of pipeline elements, which can be expressed both in the Anglo-American inch and in the metric European system. However, there is no formula for converting "pipe inches" to millimeters or "regular" inches in order to find out the actual outer or inner diameter of the pipe. The conditional passage in the metric system is also weakly related to the geometric diameter of the pipes. For an unambiguous comparison of the conditional inch diameter with the standard outer diameter of the pipe and pipe thread diameters, it is necessary to use reference literature and regulatory documentation.

GOST 3262 establishes specifications for steel pipes used for water and gas pipelines, but it does not standardize and does not mean pipe diameter in inches. When cutting pipe threads, you must be guided by GOST 6357, which establishes the main dimensions of cylindrical pipe threads in millimeters, but uses the notation thread size in inches. Thus, in order to establish a correspondence between the inch size of a pipe and its actual geometric diameter, it is necessary to compare the data given in these two standards.

For example, the outer diameter of a ½ "pipe in accordance with GOSTs is 21.3 mm, and 5" pipes - 140.0 mm. When trying to calculate the conversion factor, it turns out that " pipe inches"- more than the standard value of 25.4 mm and "different" for different pipe diameters.

The above table is built on the basis of the above-mentioned GOSTs, but does not claim to be complete and cannot serve as a substitute for official regulatory documentation.

Thread size designation	Nominal pipe diameter	Outer diameter of external thread (pipe), mm	Outer pipe diameter, mm
⅛	6	9,728	10,2
¼	8	13,157	13,5
⅜	10	16,662	17,0
½	15	20,955	21,3
¾	20	26,441	26,8
1	25	33,249	33,5
1¼	32	41,910	42,3
1½	40	47,803	48,0
2	50	59,614	60,0
2½	65	75,184	75,5
3	80	87,884	88,5
3½	90	100,330	101,3
4	100	113,030	114,0
5	125	138,430	140,0
6	150	163,830	165,0

Plan
Introduction
1 Different inches
1.1 Austria-Hungary
1.2 UK
1.3 Germany
1.4 Spain
1.5 Quebec
1.6 China
1.7 Mexico
1.8 Ostsee counties
1.9 Commonwealth, Poland
1.10 Rio de la Plata
1.11 US
1.12 France
1.13 Japan
1.14 Vidicon inch

2 inches in Russia
3 Designation
4 Origin
Bibliography

Introduction

1. Different inches

Austria-Hungary Vienna inch = 2.6340278 cm. UK

English inch or imperial inch(English) inch from lat. uncia- 1/12 part) since 1958 is equal to exactly 2.54 cm. Previously, it was converted to the metric system in a different way:

1819 - 1000000/393694 cm ≈ 2.5400438 cm;
1895 - 2.5399978 cm;
1922 - 2.5399956 cm;
1932 - 2.5399950 cm;
1947 - 2.5399931 cm.

In English units, 1 inch = 12 lines = 72 points = 1/12 foot = 1/36 yard.

1.3. Germany

Bavaria: 2.43216 cm or 2.918592 cm ("decimal inch");
Baden: 3 cm (1810);
Prussia: 2.61545 cm (1755), 3.76625 cm ("decimal inch", 1816);
Confederation of the Rhine: 2.61541 cm;
Saxony: 2.36 cm.

Spain 1 pulgada = 2.32166 cm. Quebec French inch was used, but since 1985 the value has changed: 2.707005 cm. China 1 cun = 1/30 m ≈ 3.33333 cm. Mexico

1 pulgada = 2.3278 cm.

1.8. Ostsee provinces

Along with Rhine inches (see above, in the section on Germany), the following were used:

Courland inch≈ 3.36 cm;
Riga inch≈ 2.24 cm;
revel inch≈ 2.6715 cm.

1.9. Commonwealth, Poland

Old Polish or crown inch(until 1819) ≈ 2.48 cm;
novopol inch(1819-1849) = exactly 2.4 cm;
Wroclaw (Breslav, Silesian) inch= 2.742 cm;
old Lithuanian inch≈ 2.7076 cm.

Rio de la Plata1 pulgada ≈ 2.547 cm. USA

1.12. France

Japan 1 sun = 1/33 m ≈ 3.0 cm Widicon inch

Equals 2/3 of an ordinary inch or 16.93mm. Most often it is used to measure the diagonal of the matrix of digital cameras.

For example, 1 / 2.7 "is 1 divided by 2.7 and multiplied by 16.93mm i.e. 6.27mm

2. Inches in Russia

After the USSR switched to the metric system, inches as such were practically forgotten and were used to a limited extent: in the mains of water supply and gas, the inch calculation (using integer fractions of an inch) remained for pipe diameters; some calibers of artillery were unofficially expressed (the most famous are “three-inchers” - guns of 76.2 mm caliber), small arms (“three-rulers” - 7.62 mm), the length of nails, the thickness of boards and the size of some other objects, although the actual values \u200b\u200bof the sizes of various technical products quite often in inches (or other units of the old system) were expressed in rounder numbers than in the metric system.

In recent years, under the influence of American technology and technical terminology, inches are used much more often in Russian. In particular, they express the size of various computer parts, assemblies and accessories: floppy disks, hard drives, displays, etc. In "dots per inch" (dpi) and "lines per inch" (lpi), the resolution of various graphics devices is measured. input-output. The screen diagonal of household television broadcast receivers, measured in centimeters in Soviet times, is now often indicated in inches. The diameter of car rims is also traditionally measured in inches (at the same time, tire dimensions and fastener parameters are in the metric system)

3. Designation

In modern Russian, there is no generally accepted letter abbreviation for inches (before the transition to the metric system, “dm” was used, but now decimeters are denoted this way). The English designation is most often copied: the same double stroke as in the designation of arcseconds ( ″ - U+2033), placed without a space after the numerical value, for example: 3″ (3 inches). In English-speaking countries, the abbreviation "in" is also used (from the English. inch- inch): "3 in".

4. Origin

Bibliography:

Pipes steel water and gas GOST 3262-75

Metrological parameters of pipes according to GOST 3262-75

Widely used diameters and compliance with the conditional passage (in fractions of inches) of the nominal size (in mm): 1/8 inch - 6 mm; 1/4 inch - 8 mm; 3/8 inch - 10 mm; 1/2 - 15 mm; 3/4 - 20 mm; one inch - 25 mm; an inch and a quarter - 32 mm; one and a half inches - 40 mm; two inches - 50 mm; two and a half inches - 65 mm; 4 inches - 100 mm.