1 2 inches in mm. What is the size of inch pipes in mm? An example of how to enter data into a calculator

inches	mm.	inches	mm.	inches	mm.	inches	mm.	inches	mm.
-	-	1	25,4	2	50,8	3	76,2	4	101,6
1/8	3,2	1 1/8	28,6	2 1/8	54,0	3 1/8	79,4	4 1/8	104,8
1/4	6,4	1 1/4	31,8	2 1/4	57,2	3 1/4	82,6	4 1/4	108,8
3/8	9,5	1 3/8	34,9	2 3/8	60,3	3 3/8	85,7	4 3/8	111,1
1/2	12,7	1 1/2	38,1	2 1/2	63,5	3 1/2	88,9	4 1/2	114,3
5/8	15,9	1 5/8	41,3	2 5/8	66,7	3 5/8	92,1	4 5/8	117,5
3/4	19,0	1 3/4	44,4	2 3/4	69,8	3 3/4	95,2	4 3/4	120,6
7/8	22,2	1 7/8	47,6	2 7/8	73,0	3 7/8	98,4	4 7/8	123,8

Inch thread parameters

External diameter of the pipe to be connected		SAE thread rating	Thread rating UNF	Thread outer diameter, mm	Average thread diameter, mm	thread pitch
mm	inch					mm	thread/inch
6	1/4""""	1/4""""	7/16""""-20	11,079	9,738	1,27	20
8	5/16""""	5/16""""	5/8""""-18	15,839	14,348	1,411	18
10	3/8""""	3/8""""	5/8""""-18	15,839	14,348	1,411	18
12	1/2""""	1/2""""	3/4""""-16	19,012	17,33	1,588	16
16	5/8""""	5/8""""	7/8""""-14	22,184	20,262	1,814	14
18	3/4""""	3/4""""	1""""-14	25,357	23,437	1,814	14
18	3/4""""	---	1""""1/16-14	26,947	25,024	1,814	14
20	7/8""""	---	1""""1/8-12	28,529	26,284	2,117	12
22	7/8""""	7/8""""	1""""1/4-12	31,704	29,459	2,117	12
22	7/8""""	---	1""""3/8-12	34,877	32,634	2,117	12
25	1""""	1""""	1""""1/2-12	38,052	35,809	2,117	12

Copper conductors, wires and cables

Conductor cross section, mm	Copper conductors, wires and cables
	Voltage, 220 V		Voltage, 380 V
	current, A	power, kWt	current, A	power, kWt
1,5	19	4,1	16	10,5
2,5	27	5,9	25	16,5
4	38	8,3	30	19,8
6	46	10,1	40	26,4
10	70	15,4	50	33,0
16	85	18,7	75	49,5
25	115	25,3	90	59,4
35	135	29,7	115	75,9
50	175	38,5	145	95,7
70	215	47,3	180	118,8
95	260	57,2	220	145,2
120	300	66,0	260	171,6

Aluminum conductors, wires and cables

Conductor cross section, mm	Aluminum conductors, wires and cables
	Voltage, 220 V		Voltage, 380 V
	current, A	power, kWt	current, A	power, kWt
2,5	20	4,4	19	12,5
4	28	6,1	29	15,1
6	36	7,9	30	19,8
10	50	11,0	39	25,7
16	60	13,2	55	36,3
25	85	18,7	70	46,2
35	100	22,0	85	56,1
50	135	29,7	110	72,6
70	165	36,3	140	92,4
95	200	44,0	170	112,2
120	230	50,6	200	132,0

Inch thread sizes

	Thread diameter in mm			Thread pitch in mm	Number of threads per 1"
	outer d	middle d	inner d
3/16	4,762	4,085	3,408	1,058	24
1/4	6,350	5,537	4,724	1,270	20
5/16	7,938	7,034	6,131	1,411	18
3/8	9,525	8,509	7,492	1,588	16
1/2	12,700	11,345	9,989	2,117	12
5,8	15,875	14,397	12,918	2,309	11
3/4	19,05	17,424	15,798	2,540	10
7/8	22,225	20,418	18,611	2,822	9
1	25,400	23,367	21,334	3,175	8
1 1/8	28,575	26,252	23,929	3,629	7
1 1/4	31,750	29,427	27,104	3,629	7
1 1/2	38,100	35,39	32,679	4,233	6
1 3/4	44,450	41,198	37,945	5,080	5
2	50,800	47,186	43,572	5,644	4 1/2

Nominal thread diameter in inches
	Thread diameter in mm			Thread pitch in mm	Number of threads per 1"
	outer d	middle d	inner d
1/8	9,729	9,148	8,567	0,907	28
1/4	13,158	12,302	11,446	1,337	19
3/8	16,663	15,807	14,951	1,337	19
1/2	20,956	19,794	18,632	1,814	14
5/8	22,912	21,750	20,588	1,814	14
3/4	26,442	25,281	24,119	1,814	14
7/8	30,202	29,040	27,878	1,814	14
1	33,250	31,771	30.293	2,309	11
1 1/8	37,898	36,420	34,941	2,309	11
1 1/4	41,912	40,433	38,954	2,309	11
1 3/8	44,325	32,846	41,367	2,309	11
1 1/2	47,805	46,326	44,847	2,309	11
1 3/4	53,748	52,270	50,791	2,309	11
2	59,616	58,137	56,659	2,309	11

Unit conversion table

Conversion of energy units	Converting pressure units
1 J = 0.24 cal	1 Pa = 1 N/m*m
1 kJ = 0.28 W*h	1 Pa \u003d 0.102 kgf / m * m
1 W = 1 J/s	1 atm = 0.101 MPa = 1.013 bar
1 cal = 4.2 J	1 bar = 100 kPa = 0.987 atm
1 kcal/h = 1.163 W	1 PSI = 0.06895 bar = 0.06805 atm

Inch to metric conversion tables. Thread size: table of metric and inch threads

The process of selecting the required cross-sectional dimensions of threads, cables and pipes is often time consuming. In addition to the fact that it is necessary to choose the appropriate dimensions, taking into account the parameters of the equipment, the customer has to independently convert the data into suitable units of measurement. This process is costly in terms of time.

We simplify this task, as we suggest you use ready-made translation tables. On the page of our website you will find tables that will help you easily select the necessary threads for inch pipes, copper and aluminum conductors of wires and cables. Also, you can use the inch to metric conversion table, thereby accurately calculate the required cross-sectional dimensions.

Unfortunately, most equipment manufacturers leave the customer alone with the calculations. Therefore, a person has to independently search the Internet for translation tables in order to select the optimal sizes of wire cross-sections and pipe diameters.

We value the time of our customers, providing everyone with the opportunity to use ready-made solutions. Our tables convert standard sizes from inches to millimeters.

On this page you will also find translations of the main energy units and pressure units, therefore, you will be able to choose the right refrigeration equipment, taking into account the individual conditions of placement and operating modes of the units.

In the construction market, 2 sizes of structures are popular:

• 1\2 and 3\4 - make up a separate category. due to special thread parameters (1.814), per 1 unit. measures accounted for 14 strands;
• within 1 - 6 inches, the pitch is reduced to 2.309, forming 11 threads that do not affect the decrease or increase in the quality of the connection.

One inch is 25.4 mm long, it is used to determine the internal parameters, but when laying reinforced pipes, the diameter is 33.249 mm (including the internal section and 2 walls). There is an exception in the range of steel structures - products in ½ inch, where the outer section is 21.25 mm. This parameter is used when calculating the dimensions of pipes with cylindrical threads. When calculating for pipes with a cross section of 5 inches, the internal dimension will be 12.7 cm, and the external - 166.245 (reduced to 1 decimal place is allowed).

The difference between measurement systems

In terms of external parameters, inch designs do not differ from metric ones, the difference lies in the type of notches. There are 2 types of threads according to the inch system - English and American. The first option corresponds to a notch angle of 55 degrees, and the metric (American) system with an angle of 60 degrees. generally accepted.

At different degrees, it is difficult to distinguish the angle by 55 for inch and 60 for metric designs, and the rounding of the threads is immediately visible, the occurrence of an error is impossible. A thread gauge is used to measure the thread pitch, but an ordinary ruler or other device is well used instead.

Replacing steel pipes with polymer ones

In the gas and water supply network, steel products are used, the diameter of which is indicated in inches (1", 2") or fractions (1/2", 3/4"). When measuring a 1" pipe cross-section, the result is 33.5 mm, which corresponds to 1" (25.4 mm). When arranging pipeline reinforcing elements, where the parameters are indicated in inches, there are no difficulties. But when installing products made of PP, copper or stainless steel instead of steel structures, it is required to take into account the difference in the name and parameters.

To create a given level of flow, the internal diameter of the pipes is taken into account. For inch ordinary pipes, it is 27.1 mm, for reinforced 25.5 mm, closest to 1 ". Pipelines are designated in conventional units of the flow area Du (DN). It determines the parameters of the pipe clearance and is indicated in digital values. sections are selected taking into account the increase in throughput characteristics by 40-60% with an increase in the index.If the external cross section and the purpose of the structures are known, using the size table, the internal cross section is determined.

In the process of connecting steel pipes with polymer structures, replacing one with another, conventional adapters are used. Dimensional mismatch results from the use of copper, aluminum or stainless steel products manufactured to metric standards. The actual metric dimensions of the pipes are taken into account - internal and external.

Steel pipes of the Russian Federation in comparison with the European standard

To compare the range of pipes according to GOST RF and European standards, the following table is used:

How to decide on the choice of diameter?

Their throughput characteristics depend on the diameter of water pipes - the volume of water passed for 1 unit. time. It depends on the speed of the water flow. With its increase, the risk of pressure drop in the line increases. Throughput characteristics are calculated according to formulas, but when planning intra-apartment wiring, they take pipes of certain parameters.

For the plumbing system:

• 1.5 cm (1/2 inch)
• 1 cm (3/8 inch).

For the riser, structures with an internal cross section are used:

• 2.5 cm (1 inch);
• 2 cm (3/4 inch).

Given that the internal cross section of half-inch polymer pipes varies from 11 to 13 mm, and one-inch pipes from 21 to 23, an experienced plumber will be able to determine the exact parameters when replacing. With a complex type of wiring, numerous joints, turns and laying the network at a great distance, reducing the pressure, it should be possible to carry out the wiring of pipes with a large cross section. As the diameter increases, the pressure level increases.

Below is a table for determining the patency of steel pipes:

Steel pipe diameter

The cross section of the pipes corresponds to a number of indicators:

• Nominal diameter (Dn, Dy) - nominal parameters (in mm) of the internal cross-section of pipes or their rounded indicators, in inches.
• Rated value (Dn Dn,).
• external size.

  The metric calculation system allows classifying structures into small ones - from 5 ... 102 mm, medium - from 102 ... 426, large - 426 mm and more.

• Wall thickness.
• inner diameter.

The internal cross section of pipes with different threads corresponds to the following parameters:

• 1/2 inch pipeline - 1.27 cm;
• 3/4 inch - 1.9 cm;
• 7/8 inch - 2.22 cm;
• 1 inch - 2.54 cm;
• 1.5 inches - 3.81 cm;
• 2 inches - 5.08 cm.

The following indicators are used to determine the thread diameter:

• pipeline 1/2 inch - 2.04 - 2.07 cm;
• 3/4 inches - 2.59 - 2.62 cm;
• 7/8 inch - 2.99 - 3 cm;
• 1 inch - 3.27 - 3.3 cm;
• 1.5 inches - 4.58 - 4.62 cm;
• 2 inches - 5.79 - 5.83 cm.

Table of correspondence between the diameter of steel pipes and polymer structures:

Steel pipe prices:

Pipe diameter PP

PP pipes are produced with a diameter of 0.5 to 40 cm or more. The diameter is internal and external. The first indicator allows you to find out the volume of environments traversed in 1 unit. time. The external cross section is used for construction calculations, namely the choice of a niche or pit for laying a highway. External parameters allow you to choose the right fittings with the corresponding internal indicators.

• Small - 0.5; one; 1.5; 2; 2.5; 3.2; 4; 5; 6.3 and 7.5 cm is used for heating systems, drains and water supply in private buildings. An internal cross section of 3.2 cm is most popular in multi-storey buildings.
• Medium - 8; nine; ten; eleven; 12.5; sixteen; 20; 25 and 31.5 cm is used for arranging water supply and sewer systems, allowing you to change cast iron products with similar external parameters. Internal dimensions of 8, 9 and 10 cm are ideal for chemical environments.
• Large - 40 cm or more is used for arranging cold water supply and ventilation systems.

Pipes are marked in inches and mm. When choosing structures for the plumbing and heating systems, the wall thickness is taken into account, which affects the conditional patency of highways with the same external parameters. With an increase in its parameter, an increase in pressure in the plumbing system is allowed. Small dimensions allow to reduce the level of costs for the purchase of material and water consumption.

Cost of PP pipes:

Video

The diameter of the pipes in inches and millimeters are very important indicators. Many have faced the challenge of replacing or installing piping and finding the right materials for the job.

It is difficult to understand the huge number of proposals on the construction market, therefore, before buying, you should study in detail what the volume of pipe rolling is and how it is used in practice.

You can immediately use the online calculator below for translation without familiarizing yourself with the theory.

Online calculator for converting inches to millimeters and vice versa

An example of how to enter data into a calculator

In writing the size in inches, you should separate the integer part of the number from the fractional (if any) with a space: for example, 10 1/4, or 20 4/8; otherwise you get 101/4 and 204/8. Fractional numbers in millimeters are entered through a dot, not a comma (25.4 and not 25.4).

Enter the data for the calculation in the following. in order: click the left mouse button in the window of the corresponding parameter to make the blinking cursor appear; enter your numbers. The fractional part of an inch is entered without a sign.

1 inch = 25.4 millimeters (mm). Currently, an inch, due to its clarity, is often used to measure the diameters of water and gas pipes and threads. Many parts are also sized in multiples of inches. In addition to whole inches, measurements are taken in fourths (1/4″), eighths (1/8″), sixteenths (1/16″), thirty-seconds (1/32″) of an inch, etc.

If you have any questions about using the online calculator, you can always ask a question in the comment form. We also strongly recommend that you read the instructions (located under the calculator).

How to convert inch values ​​​​to metric notation

The conversion of inches to metric pipe volumes is performed using special tables. Here is an example of such a table:

In order to convert the metric diameter of the pipe assortment, it is necessary to perform rounding in the direction of increase. When making this translation, you need to remember that according to international standards, one inch is taken into account as 2.54 cm.

With such data, the translation can be performed using the simplest calculator. Now that the cross section of the pipe assortment has been calculated, its volume should be correctly calculated.

In practice, in order to translate the measurements of steel options, it must be taken into account that the inch indicators in the calculation will not be equal to the indicator in mm. The reason is that when marking, the internal volume is prescribed.

After the unit of measurement, the conditional passage, indicated by an integer, becomes. It is for these reasons that in order to translate values, they need to be rounded. It is difficult for an inexperienced master to make such a translation.

Therefore, if you need to translate these indicators, it is better to seek help from professionals, or perform a translation based on a special table. Professionals will help translate the required values, and help you choose the right products and other parts for the pipeline.

Translation tables

In the construction of highways for various purposes, different pipe materials are used: steel, copper, brass, plastic, and others. All these products are distinguished by classification and measurement measures.

The overall dimensions of all tubular products are given by the following indicators:

• Dn - external Ø.
• Dv - internal Ø.
• h is the wall thickness.

Previously, only steel lines were used, and for them they created their own sizing system. . These are its internal dimensions. That is, this indicator takes into account not only the size of a half-inch pipe billet, but also its throughput.

And the outer girth of a half-inch blank is 2.1 cm. Therefore, in the table near the half-inch thread, the word pipes must be added. Knowing the exact dimensions of the half-inch and any other type of assortment, you can quickly make the right choice of the right volumes.

This is clearly seen in the table:

Dimensions (in inches)	1/2	3/4	7/8	1	1,5	2
Internal Ø (in metric)	12,7	19	22,2	25,4	38,1	50,8
Thread Ø (mm)	20,4-20,7	25,9-26,2	29,9-30,0	32,7 – 33,0	45,8 – 46,2	57,9 – 58,3

Now it is customary to indicate these dimensions as shown in the following table provided:

The first table of diameters ( its symbolic designation is Ø, further it will be denoted in the article) of pipes shows values ​​in millimeters, while inches are used in the second table ( international designation - inch or in, will be further indicated in the article). An inexperienced master may ask why? And what designations are considered correct?

The reason is that the metric system is used all over the world. This system is based on two indicators: conditional and nominal volume. These concepts are approached in different ways, but in the end they show the external volume. In essence, these quantities are dimensionless, but sometimes they are indicated in millimeters.

Analyzing tabular data, it is possible to compare products of domestic manufacturers and analogues of foreign production.

Interesting! Measurement discrepancies appeared simultaneously with the introduction of copper systems in Europe in the second half of the 20th century. In Russia, at that time, the standards for the metal assortment were determined in mm, and not in inch, this measurement system is widely used today.

Correspondence of two notation systems

Steel pipes are widely used in water and gas systems. Their dimensions are shown in whole values ​​or their fractions. For example, a 1" tubular in mm would be 33.5, and a 2" tubular would be 67 in mm.

This of course does not correspond to the declared 25.4 and 50 mm. When laying fittings with inch designations for 1 and 2 inch products, there are no difficulties, but replacing with plastic and copper products requires taking into account the discrepancy in the designations.

Why is everything so complicated? The fact is that for the formation of a fluid flow, it is important to take into account the internal size. For these reasons, they began to indicate exactly this indicator for 1-inch, 2-inch and all other pipe materials. The most accurate indicators are considered in terms of conditional passage.

The nominal bore of 1-inch, 2-inch and the rest of the pipe range is equal to the dimensions of the clearance. To indicate the metric size of 1 inch, 2 inch and any other pipeline, it is recommended to use tables.

Precise definitions - formula for calculation

This knowledge is needed to calculate the amount of transported medium. This is very important for heating systems. For example, when it is necessary to lay a heating system, it is necessary to determine and calculate the size of the assortment in the section so that all housing is heated evenly.

How to accurately determine the cross section of each pipe in quantities such as inches can be suggested by the formula: D \u003d sqrt ((314 ∙ Q) / (V ∙ DT)).

• D is the internal volume of the pipe;
• Q is the heat flux, which is determined in kW;
• V denotes the speed of the heat carrier, it is determined in m / s;
• DT is the difference in temperature indicators at the inlet and outlet of the network;
• sqrt is the square root.

Watch the video

Despite the presence of formulas, tables help to quickly determine Ø. In this way, a lot of time is saved.

What is inch volume

Deciphering the diameter of the pipes provided in inches is simple. They are often measured in these quantities. Such one unit is equal to 3.35 cm. It has already been indicated that the interpretation of this value has discrepancies, and this is due to the fact that the assortment is measured not by the external volume, but by the internal one. So, for example, the internal dimension of an inch pipe billet can be different: from 2.55 to 2.71 cm. This value varies depending on the wall thickness.

A 1 inch pipe has an outer diameter of 25.4 mm, a 2 inch pipe is 50 millimeters in metric measurement. Where do the numbers 33.249 and 66.498 come from in the technical parameters of a cylindrical pipe thread?

This thread on 1 and 2 inch products is performed on the outer volume. Therefore, the ratio of the thread diameter to the internal volume is conditional. Based on this, the dimensions of 1 and 2 inch tubing are calculated by adding the value of 25, 4 or 50 with two wall thicknesses of the tubular product.

Before deciphering, you need to take into account that measurements of the product must be performed not from the outside, but from the inside. Why is this needed? The fact is that by fastening sections of the highway from different materials, and taking measurements only from the outside, you can get the wrong result, which will lead to an error, since the entire assortment differs in wall dimensions.

Also, when deciphering, we must not forget that the standards of different manufacturers are different, they all focus on their own indicators.

If it is difficult to perform such decryption on your own, then you should seek help from professionals. They will provide effective assistance in choosing the right products.

Correspondence of metric and inch parameters

All tubular products are manufactured according to a certain standard, and the pressure indicator is a fixed value. Therefore, you need to know exactly the correspondence of the Ø of all pipes shown in inches and mm. Ignoring this correspondence, it is impossible to choose the right pipe assortment.

Watch the video

When selecting a certain size, they are guided by tabular information, and when replacing a guide, we serve as the most approximate parameter. There is no exact correspondence in two different systems of measurement, therefore pipeline elements are often equated in practice.

How this correspondence is applied in everyday life can be found in the table below:

Using this information, you can accurately determine the correspondence of two types of measurements of dimensions, and take parts for work that exactly match each other.

Inch size expression

These indicators are written as an integer, a double stroke is placed next to it, for example, 3 ". Also, the dimensions of the pipe diameter, transmitted in inches, are prescribed in fractions, for example, ½.

If we consider these dimensions on specific examples of Du correspondences, then they will look like this:

1. The diameter of a standard 12 inch pipe is 300.
2. 3 inch tubular diameter is 80.
3. 8 inch diameter of standard pipe is equal to 200.
4. The diameter of a standard pipe, at 32, when translated into inches, is shown as 1 ¼
5. Pipe diameter 40 mm in inch prescribe 1 ½
6. Ø standard pipe at 15 inches is expressed as a number ½
7. The Ø of a standard product per 4 inches in terms of metric is 100.
8. Ø 3/4 inch pipe in metric conversion is 20.
9. The Ø of a standard 1/2 inch pipe in metric translation shows the number 15.

Watch the video

Pipe diameter in inches and millimeters is used all the time. Knowing these dimensions, you can avoid great difficulties when connecting pipeline elements. And special tables help to find the necessary dimensions of the docking parts and correctly fit them.

Very often on the packaging (box) with a mixer, in the list of product characteristics, you can see the figure 3/8 inch in the column "connecting size".

What is this size, and how will we connect the mixer if we purchase it?

Connecting size 3/8 inch, corresponds to M10 metric thread. These are the dimensions of the threaded connection of the fitting part of the flexible hose. On one side of such a hose, clad in a metal braid, a turnkey fitting of 10 or 11 millimeters and a thread at the end of 10 millimeters, or 9.5 millimeters, which corresponds to three-eighths of an inch.

They look like this.

First, a short fitting is screwed to the mixer, followed by a long one. This is so that the edges of the fittings and the thickening of the crimping do not interfere with each other.

There is an alternative for reinforced flexible hoses - bellows hoses for faucets. They are not much more expensive, but their service life is a multiple of the service life of a rubber braided hose. So if the usual flexible eyeliner lasts 3-4 years, then the bellows pipe lasts up to 10 years.

At the second end, a flexible hose can have a thread instead of a nut, complete with mixers, more often there is a nut, so consider if there is a nut at the outlet of your pipeline, you will need to purchase a nipple -