1 2" internal diameter. Convert plumbing inches to millimeters

Her Majesty the trumpet! Of course, it makes our lives better. Like that:

The key characteristic of any cylindrical pipe is its diameter. It can be internal ( Du) and external ( Dn). Pipe diameter is measured in millimeters, but the unit of pipe thread is inch.

At the junction of the metric and foreign measurement systems, the most questions usually arise.

Besides, it's real existing size internal diameter often does not coincide with Dy.

Let's take a closer look at how we can continue to live with this. Pipe thread a separate article is devoted. Read also about profile pipes, which are used for the construction of structures.

Inches vs mm. Where does the confusion come from and when is a correspondence table needed?

Pipes whose diameter is indicated in inches ( 1", 2" ) and/or fractions of inches ( 1/2", 3/4" ), are a generally accepted standard in water and water-gas supply.

What's the difficulty?

Take dimensions from the pipe diameter 1" (how to measure pipes is written below) and you will get 33.5 mm, which naturally does not coincide with the classical linear table for converting inches to mm ( 25.4 mm).

As a rule, installation of inch pipes occurs without difficulties, but when replacing them with pipes made of plastic, copper and of stainless steel a problem arises - the size of the designated inch does not match ( 33.5 mm) to his actual size (25.4 mm).

Usually this fact causes bewilderment, but if you look deeper into the processes occurring in the pipe, the logic of the size discrepancy becomes obvious to a layman. It's quite simple - read on.

The fact is that when creating a water flow, the key role is played not by the external, but by inner diameter and for this reason it is used for the designation.

However, the discrepancy between designated and metric inches still remains, since the internal diameter of a standard pipe is 27.1 mm, and reinforced - 25.5 mm. The last value is quite close to equality 1""=25,4 but still he is not.

The solution is that to indicate the size of pipes, a nominal value is used, rounded to standard value diameter (nominal diameter Dy). The nominal diameter is selected so that throughput pipeline increased from 40 to 60% depending on the growth of the index value.

Example:

Outside diameter pipe system is equal to 159 mm, pipe wall thickness 7 mm. The exact inner diameter will be D = 159 - 7*2= 145 mm. With wall thickness 5 mm size will be 149 mm. However, in both the first and second cases, the conditional passage will have the same nominal size 150 mm.

In situations with plastic pipes To solve the problem of inappropriate dimensions, transition elements are used. If it is necessary to replace or connect inch pipes with pipes made according to real metric dimensions - copper, stainless steel, aluminum, both the outer and inner diameters should be taken into account.

Table of nominal diameter in inches

Du	Inches	Du	Inches	Du	Inches
6	1/8"	150	6"	900	36"
8	1/4"	175	7"	1000	40"
10	3/8"	200	8"	1050	42"
15	1/2"	225	9"	1100	44"
20	3/4"	250	10"	1200	48"
25	1"	275	11"	1300	52"
32	1(1/4)"	300	12"	1400	56"
40	1(1/2)"	350	14"	1500	60"
50	2"	400	16"	1600	64"
65	2(1/2)"	450	18"	1700	68"
80	3"	500	20"	1800	72"
90	3(1/2)"	600	24"	1900	76"
100	4"	700	28"	2000	80"
125	5"	800	32"	2200	88"

Table. Inner and outer diameters. Stacked water/water-gas pipelines, epectros-welded longitudinal, seamless hot-deformed steel and polymer pipes

Table of correspondence between nominal diameter, thread and outer diameters of the pipeline in inches and mm.

Nominal pipe diameter Dy. mm	Thread diameter G". inch	Pipe outer diameter Dn. mm
		Water/water-gas pipes GOST 3263-75	Epoxy-welded straight-seam steel pipes GOST 10704-91. Seamless hot-deformed steel pipes GOST 8732-78. GOST 8731-74 (FROM 20 TO 530 ml)	Polymer pipe. PE, PP, PVC

GOST- state standard used in heat - gas - oil - pipelines

ISO- standard for designating diameters, used in plumbing engineering systems

SMS- Swedish standard for pipe diameters and valves

DIN/EN- the main European range for steel pipes according to DIN2448 / DIN2458

DU (Dy)- conditional pass

Size tables polypropylene pipes presented in the next article >>>

Conformity table for nominal pipe diameters with international markings

GOST	ISO inch	ISO mm	SMS mm	DIN mm	DU
8	1/8	10,30			5
10	1/4	13,70	6,35		8
12	3/8	17,20	9,54	12,00	10
18	1/2	21,30	12,70	18,00	15
25	3/4	26,90	19,05	23(23)	20
32	1	33,70	25,00	28,00	25
38	1 ¼	42,40	31,75	34(35)	32
45	1 ½	48,30	38,00	40,43	40
57	2	60,30	50,80	52,53	50
76	2 ½	76,10	63,50	70,00	65
89	3	88,90	76,10	84,85	80
108	4	114,30	101,60	104,00	100
133	5	139,70	129,00	129,00	125
159	6	168,30	154,00	154,00	150
219	8	219,00	204,00	204,00	200
273	10	273,00	254,00	254,00	250

Diameters and other characteristics of stainless steel pipes

Passage, mm	Diameter external, mm	Wall thickness, mm		Weight of 1 m pipe (kg)
		standard	reinforced	standard	reinforced
10	17	2.2	2.8	0.61	0.74
15	21.3	2.8	3.2	1.28	1.43
20	26.8	2.8	3.2	1.66	1.86
25	33.5	3.2	4	2.39	2.91
32	42.3	3.2	4	3.09	3.78
40	48	3.5	4	3.84	4.34
50	60	3.5	4.5	4.88	6.16
65	75.5	4	4.5	7.05	7.88
80	88.5	4	4.5	8.34	9.32
100	114	4.5	5	12.15	13.44
125	140	4.5	5.5	15.04	18.24
150	165	4.5	5.5	17.81	21.63

Did you know?

What ingenious lamps can you assemble with your own hands from ordinary metal pipe? Anyone can do this!

Which pipe is considered small - medium - large?

Even in serious sources I have seen phrases like: “We take any pipe of average diameter and...”, but no one indicates what this average diameter is.

To figure it out, you should first understand what diameter you need to focus on: it can be internal or external. The first is important when calculating the transport capacity of water or gas, and the second is important for determining the ability to withstand mechanical loads.

External diameters:

From 426 mm is considered large;

102-246 is called average;

5-102 is classified as small.

As for the internal diameter, it is better to look at the special table (see above).

How to find out the diameter of a pipe? Measure!

For some reason this strange question often comes to e-mail and I decided to supplement the material with a paragraph about measurement.

In most cases, when purchasing, it is enough to look at the label or ask the seller a question. But it happens that you need to repair one of the communication systems by replacing pipes, and initially it is not known what diameter the already installed ones have.

There are several ways to determine the diameter, but we will list only the simplest ones:

Arm yourself with a tape measure or a measuring tape (this is how women measure their waist). Wrap it around the pipe and record the measurement. Now, to obtain the desired characteristic, it is enough to divide the resulting figure by 3.1415 - this is the number Pi.

Example:

Let's imagine that the girth (circumference L) of your pipe is 59.2 mm. L=ΠD, resp. the diameter will be: 59.2 / 3.1415= 18.85 mm.

• After obtaining the outer diameter, you can find out the inner one. Only for this you need to know the thickness of the walls (if there is a cut, just measure with a tape measure or other device with a millimeter scale).

  Let's assume that the wall thickness is 1 mm. This figure is multiplied by 2 (if the thickness is 3 mm, then it is also multiplied by 2 in any case) and subtracted from the outer diameter (18.85- (2 x 1 mm) = 16.85 mm).

  It’s great if you have a caliper at home. The pipe is simply grabbed by the measuring teeth. Required value look at the double scale.

Types of steel pipes according to their production method

Electric welded (straight seam)

For their manufacture, strips or sheet steel are used, which are bent into shape using special equipment. required diameter, and then the ends are connected by welding.

The effect of electric welding guarantees a minimum seam width, which makes it possible to use them for the construction of gas or water pipelines. The metal is in most cases carbon or low alloy.

Indicators finished products are regulated by the following documents: GOST 10704-91, GOST 10705-80 GOST 10706-76.

Please note that a pipe manufactured in accordance with standard 10706-26 is distinguished by maximum strength among its peers - after creating the first connecting seam, it is strengthened by four additional ones (2 inside and 2 outside).

The regulatory documentation indicates the diameters of products produced by electric welding. Their size ranges from 10 to 1420 mm.

Spiral seam

The material for production is steel in rolls. The product is also characterized by the presence of a seam, but unlike the previous production method, it is wider, which means the ability to withstand high internal pressure is lower. Therefore, they are not used for the construction of gas pipeline systems.

A specific type of pipe is regulated by GOST number 8696-74 .

Seamless

The production of a specific type involves the deformation of specially prepared steel blanks. The deformation process can be carried out both under the influence high temperatures, and cold method (GOST 8732-78, 8731-74 and GOST 8734-75, respectively).

The absence of a seam has a positive effect on the strength characteristics - the internal pressure is evenly distributed over the walls (there are no “weak” places).

As for diameters, standards control their production with a value of up to 250 mm. When purchasing products with sizes exceeding those indicated, you have to rely only on the integrity of the manufacturer.

It is important to know!

If you want to buy the maximum durable material, buy seamless cold-formed pipes. The absence of temperature influences has a positive effect on preserving the original characteristics of the metal.

Also, if the ability to withstand internal pressure is an important indicator, then choose round products. Profile pipes cope better with mechanical loads (they are well made from metal frames and so on.).

A couple more great slides for your attention. creative advertising pipe manufacturer:

Diameter is one of the most important dimensional characteristics of steel pipes. Thanks to such a parameter as diameter, all the necessary design calculations can be made.

Standard diameters of steel pipes are strictly regulated by GOST 10704-91.

Purely conditionally, pipe diameters are divided into the following categories:

— large diameter(more than 508 millimeters),

- medium diameter (114-530 mm)

- and small diameter (no more than 114 millimeters).

Main dimensions

It is based on these characteristics that the diameters of steel pipes are determined in accordance with GOSTs and TUs:

• internal diameter of pipes;
• the outer diameter of the pipes is their main dimensional characteristics according to GOST standards;
• nominal pipe diameter. Represents the nominal size of the internal diameter of the pipe;
• pipe wall thickness;
• nominal pipe diameter.

1. Steel pipes are classified into small, medium and large precisely according to the outer diameter (Dн). Standard diameters are shown in the table.
   
2. The most commonly used steel pipes are the following diameters: 426, 530, 159, 219, 720, 920, 273, 325, 1420 and 1220 millimeters.
3. The small outer diameter of steel pipes is used for the construction plumbing systems in apartments, houses and other premises.
4. Medium-diameter steel pipes are used for the installation of city water pipelines, as well as in field crude oil collection systems.
5. The largest diameter steel pipes are needed for the construction of main gas and oil pipelines.

Internal diameters of steel pipes

1. The internal diameter of steel pipes (Din) with a constant external diameter can vary significantly. To standardize the diameter of pipes, a term such as “nominal bore (diameter)” is used. It is designated Dу.
2. The nominal diameter is the rounded nominal size of the internal diameter. It is always rounded up only. The nominal diameter of steel pipes is determined by GOST 355-52.
3. The internal diameter can be calculated using the following formula: Din = Dn - 2S.
4. Steel pipes have internal diameters: 6, 15, 10, 20, 25, 50, 65, 32, 40, 80, 100, 125, 200.

Diameters of steel pipes in inches

In addition to millimeters, the diameter of steel pipes can also be measured in inches. One inch equals 25.4 millimeters. The table shows the diameters of steel pipes in millimeters and also in inches.

Nominal diameter of the pipe (Dy), mm	Thread diameter (G), inch	Pipe outer diameter (Dh), mm
		Steel water and gas pipe	Seamless	Polymer
10	3/8"	17	16	16
15	1/2"	21,3	20	20
20	3/4"	26,8	26	25
25	1"	33,5	32	32
32	1 1/4"	42,3	42	40
40	1 1/2"	48	45	50
50	2"	60	57	63
65	2 1/2"	75,5	76	75
80	3"	88,5	89	90
90	3 1/2"	101,3	102	110
100	4"	114	108	125
125	5"	140	133	140
150	6"	165	169	160

Video: How to make a hydraulic calculation

The description of pipe diameters contains data on all parameters - internal, external, conditional, nominal. Knowledge of the characteristics is required when installing the network and selecting fittings. Otherwise, incorrectly assembled communications threaten loss of tightness and a short service life due to breakdowns. Next, consider the pipe diameters in inches and millimeters.

Dimensional characteristics of pipes

They are reflected in the relevant GOSTs and TUs and contain the following definitions:

• The outer diameter is the main characteristic of the pipe.
• Inner diameter.
• Nominal.
• Conditional pass.

More details about the differences:

• Outside diameter classified into small, medium and large values ​​- which is why the pipe is used in the appropriate conditions. Small diameter is used in residential and private water supply systems, medium diameter is used in city communications, large diameter is used in industrial ones. Outer diameter – most important characteristic pipes, since the required fitting thread is determined from it. Designation – Dн.
• Inner diameter or true. It depends on the thickness of the wall and can differ strikingly from the external one, even if the dimensions of the latter remain unchanged. Designated as Din. It is calculated mathematically (Dн – 2S), where S is the thickness of the pipe wall. Example - the outer diameter of the pipe is 60 mm. Minus the 4 mm walls, its internal diameter will be 52 mm. As the wall thickness increases, the internal parameter decreases.
• The nominal bore or diameter of the pipe lumen is marked as Dу. This is the average internal diameter rounded up to standard parameter. For example, the outer diameter of the pipe will be 159 mm. The true internal diameter after subtracting the wall thickness of 5 mm is 149. Then the nominal diameter after rounding is 150 mm. This parameter is considered to select suitable fittings and fittings.
• Nominal diameter. The concept was introduced to standardize the marking of pipes made of different materials. The value is equal to the nominal diameter and is marked in inches. This allows you to correctly select pipes from various raw materials for combining in a network - steel and plastic are marked in inches, copper and aluminum - in millimeters.

Thus, the correct selection of components for home communications in accordance with the described concepts is not difficult. Tables for converting sizes from inches to millimeters and vice versa will help in self-repair and replacement of defective sections of networks.

Table of diameter sizes in diameters and millimeters

Nominal diameter (Dy) of the pipe, in mm	The diameter of its thread (G), in inches	Outer diameter (Dh), pipes, mm
		Steel seam pipe, water and gas supply	Seamless steel pipe	Polymer pipe

Complete table of pipe diameters

Diameters, inch	Diameters, mm
1/2	d15
3/4	d20
1'	d25
1’/1/4	d32
1’/1/2	d40
2′	d50
2’/1/2	d65
3′	d89
4'	d100

Inch	Millimeter	Inch	Millimeter
1/64	0,397	33/64	13,097
1/32	0,794	17/32	13,494
3/64	1,191	35/64	13,891
1/16	1,587	9/16	14,287
5/64	1,984	37/64	14,684
3/32	2,381	19/32	15,081
7/64	2,778	39/64	15,478
1/8	3,175	5/8	15,875
9/64	3,572	41/64	16,272
5/32	3,969	21/32	16,669
11/64	4,366	43/64	17,066
3/16	4,762	11/16	17,462
13/64	5,159	45/64	17,859
7/32	5,556	23/32	18,256
15/64	5,953	47/64	18,653
17/64	6,747	49/64	19,447
9/32	7,144	25/32	19,844
19/64	7,541	51/64	20,241
5/16	7,937	13/16	20,637
21/64	8,334	53/64	21,034
11/32	8,731	27/32	21,431
23/64	9,128	55/64	21,828
3/8	9,525	7/8	22,225
25/64	9,922	57/64	22,622
13/32	10,319	29/32	23,019
27/64	10,716	59/64	23,416
7/16	11,112	15/16	23,812
29/64	11,509	61/64	24,209
15/32	11,906	31/32	24,606
31/64	12,303	63/64	25,003

Pipe diameter in inches and millimeters is very important indicators. Many have faced the problem of replacing or installing a pipeline, and finding the appropriate materials for the job.

It is difficult to understand the huge number of proposals on the construction market, so before purchasing 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 to convert inches to millimeters and vice versa

An example of how to enter data into a calculator

When recording a size in inches, you should separate the whole part of the number from the fractional part (if any) with a space: for example, 10 1/4, or 20 4/8; otherwise it will be 101/4 and 204/8. Fractional numbers in millimeters are entered using a period rather than a comma (25.4 and not 25.4).

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

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

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

How to convert inch values ​​to metric notations

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

First table of diameters ( its symbolic designation is Ø, which will be further denoted in the article) pipes shows values ​​in millimeters, and the second table uses inches ( international designation – inch or in, which will be further designated in the article). An inexperienced master may ask why this is? And what designations are considered correct?

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

By analyzing tabular data, you can compare products from domestic manufacturers and foreign-made analogues.

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

Correspondence of two notation systems

In water and gas systems Steel pipes are widely used. Their dimensions are shown in whole quantities or their fractions. For example, the diameter of a 1-inch pipe in mm will be 33.5, and the diameter of a 2-inch pipe in mm is 67.

This of course does not correspond to the stated 25.4 and 50 mm. When laying fittings with inch markings to products of 1 and 2 inch, no difficulties arise, but replacement with plastic and copper products requires taking into account the discrepancy in the markings.

Why do they make everything so complicated? The fact is that for the formation of a liquid flow it is important to take into account inner size. For these reasons, this indicator began to be specified for 1-inch, 2-inch and all other pipe materials. The most accurate indicators are considered to be in nominal flow values.

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

Exact 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 install a heating system, you need to determine and calculate the cross-sectional size of the assortment 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 = sqrt ((314∙Q)/ (V∙DT)).

• D – internal volume of rolled pipe;
• Q is the heat flow, which is determined in kW;
• V denotes the speed of the coolant, it is determined in m/s;
• DT is the difference in temperature indicators at the input and output of the network;
• sqrt – square root.

Watch the video

Despite the presence of formulas, tables help to quickly determine Ø. This is the way to win a large number of time.

What is inch volume

Decoding the pipe diameter 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. For example, the internal dimensions of an inch pipe blank can vary: from 2.55 to 2.71 cm. This value varies depending on the wall thickness.

A pipe with a size of 1 inch has an outer diameter of 25.4 mm, a pipe with a size of 2 inch is equal to 50 millimeters in metric measurement. Where in technical parameters cylindrical pipe threads take the numbers 33.249 and 66.498?

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

Before decoding, you need to take into account that measurements of the product should be taken not from the outside, but from the inside. Why is this necessary? The fact is that by fastening sections of the main line from different materials and taking measurements only from the outside, you can get an incorrect result, which will lead to an error, since the entire assortment differs in the dimensions of the walls.

Also when decoding, we must not forget that the standards different companies– there are different manufacturers, 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 between 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 select the correct pipe range.

Watch the video

When selecting certain size are guided by tabular information, and when replacing, we use the most approximate parameter as a guide. Exact match in two different systems There is no measurement, so 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 dimensional measurements, and take parts for work that exactly match each other.

Inch size expression

These indicators are written as a whole number, with a double stroke next to it, for example, 3“. Also, the dimensions of the pipe diameter, expressed in inches, are written as a fraction, for example, ½.

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

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

Watch the video

Pipe diameters in inches and millimeters are used constantly. Knowing these dimensions, you can avoid great difficulties when connecting pipeline elements. And special tables help you find the required dimensions of the connecting parts and adjust them correctly.

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

Outer diameter of the connected pipe		SAE Thread Rating	UNF thread rating	Outer thread diameter, mm	Average thread diameter, mm	Thread pitch
mm	inch					mm	threads/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

Cross-section of current-carrying conductor, 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	average d	internal 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	average d	internal 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	Conversion of pressure units
1 J = 0.24 cal	1 Pa = 1 N/m*m
1 kJ = 0.28 Wh	1 Pa = 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

Conversion tables for inch to metric sizes. Thread size: table of metric and inch threads

The process of selecting the required cross-sectional sizes of threads, cables and pipes often takes a lot of time. In addition to the fact that it is necessary to select 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 requires significant time.

We simplify this task because we invite you to 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 wires and cables. Also, you can use the table for converting inch dimensions to metric ones, thereby accurately calculating the required section 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 optimal sizes wire sections and pipe diameters.

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

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

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