Preferred metric sizes#ISO 6708 Nominal Diameter

{{short description|Metricated industry standards}}

File:Engineering design drawings.jpg

Preferred metric sizes are a set of international standards and de facto standards that are designed to make using the metric system easier and simpler, especially in engineering and construction practices. One of the methods used to arrive at these preferred sizes is the use of preferred numbers and convenient numbers, such as the Renard series and 1-2-5 series, to limit the number of different sizes of components needed.

One of the largest benefits of such limits is an ensuing multiplicative or exponential reduction in the number of parts, tools and other items needed to support the installation and maintenance of the items built using these techniques. This occurs because eliminating one diameter fastener will typically allow the elimination of a large number of variations on that diameter (multiple thread pitches, multiple lengths, multiple tip types, multiple head types, multiple drive types, and the tools needed for installing each, including multiple drill bits (one for each different thread pitch, material, and fit combination).

Food and beverages

= Liquor bottle sizes =

International agreements, including 75/106/EEC,{{Cite web|url=http://www.welmec.org/fileadmin/user_files/publications/6-1.pdf|title=Application of Directives 75/106/EEC and 76/211/EEC concerning the marking and quantity control of e-marked prepackages|access-date=2017-10-17}} specify the capacities of liquor bottles allowed in international commerce as the following 10 sizes:

  • 100 ml ({{frac|1|10}} L)
  • 250 ml ({{frac|1|4}} L)
  • 375 ml ({{frac|3|8}} L)
  • 500 ml ({{frac|1|2}} L)
  • 750 ml ({{frac|3|4}} L)
  • 1 L
  • 1.5 L
  • 2 L
  • 3 L
  • 5 L

In the United States, the alcohol industry switched to metric bottle sizes on October 1, 1976, abandoning the existing 38 sizes of bottles and instead adopting the following 6 sizes:{{Cite news|url=https://www.nytimes.com/1976/10/11/archives/liquor-industry-converts-to-metric-system-liquor-industry-is.html|title=Liquor Industry Converts to Metric System|last=Cherry|first=Rona|work=The New York Times |date=11 October 1976 |access-date=2018-11-29|language=en}}

  • 50 mL (miniature)
  • 200 mL (replaced the half-pint) (≈237 mL is a U.S. half-pint)
  • 500 mL (replaced the pint) (≈473 mL is a U.S. pint)
  • 750 mL (replaced the fifth) (≈757 mL is a U.S. fifth)
  • 1000 mL (replaced the quart) (≈946 mL is a U.S. quart)
  • 1750 mL (replaced the half-gallon) (≈1893 mL is a half U.S. gallon)

Building construction

= System 32 furniture =

File:2017 UEF Joensuu library 06 shelf.jpg where the shelf bearing holes are placed with 32 mm distances from center to center, giving flexible choices for shelve positioning.]]

System 32 is a standard for the design and manufacture of furniture, most commonly used in the design of cabinets, wherein the major parts (sides, doors, etc.) are available in increments of 32 mm, and shelf supports consist of columns of 5 mm holes on 32 mm centers.

= ISO 2848 basic module =

File:Bjelkelag illustrasjon P1.png, where 6 M (or 6 modules) indicates a distance of 600 mm.]]

The ISO 2848 basic module is a unit of 100 mm, often represented by a single capital "M", along with 300 mm and 600 mm groupings, that is widely used for the widths of furniture in Europe.

  • A standard metric (concrete) block is 190 mm wide, 390 mm long, and 190 mm high, which allows for 10 mm mortar joints in between bricks, giving a standard unit size of 200 mm square by 400 mm long.{{Cite web|url=http://themetricmaven.com/?p=8268|title=Another Brick in the Wall|date=10 June 2017 }}
  • A standard metric brick is 90 by 57 by 190 mm; with 10 mm of mortar, that produces a standard unit of 100 mm x 200 mm.

Office equipment and supplies

= ISO 216 paper sizes =

ISO 216 standard specifies the A sizes of paper, including the very common A4, wherein the base size of A0 is one square meter, and the ratio between the height and width is \sqrt{2}, which results in all sizes of paper having the same aspect ratio.

Also related is the set of pen thicknesses for technical drawings (0.13, 0.18, 0.25, 0.35, 0.50, 0.70, 1.00, 1.40, and 2.00 mm).

Manufacturing

= ISO 261 and 262 fastener diameters =

{{main|ISO metric screw thread}}

ISO 261 defines a set of preferred metric machine screw/bolt sizes, and ISO 262 defines a subset of those; both are based roughly on Renard series as defined in ISO 3, ISO 17, and ISO 497. Given that even ISO 262 specifies a fairly large set of diameters, a much simplified set of preferred diameters was developed by one of the lead designers of ASME Z17.1 and ANSI B4.2, Knut O. Kverneland, to reduce the list to 6 preferred sizes, and another 6 intermediate supplementary sizes.{{Cite book|title=Metric Standards for Worldwide Manufacturing|last=Kverneland|first=Knut O.|publisher=Amer Society of Mechanical Engineers|year=1996|isbn=978-0791800416}}

File:Aneka Macam Mur dan Baut.jpg

File:1st_choice_metric_hex_key_set.jpg

For each size bolt or screw and type of head, there is a corresponding size driver prescribed by various ISO standards, including:

  • Internal hex drive: ISO 2936:2014 "Assembly tools for screws and nuts—Hexagon socket screw keys"{{cite web |url=https://www.iso.org/standard/60231.html |title=ISO 2936:2014 Assembly tools for screws and nuts — Hexagon socket screw keys |publisher=International Standards Organisation |access-date=2023-01-24 }}
  • External hex drive: ISO 4014, 4016, 4017, and 4018{{cite web |url=https://www.engineersedge.com/iso_hex_head_screw.htm |title=ISO Hex Head Screw Per. ISO 4014 DIN 931 ISO 4014, ISO 4016, ISO 4017, ISO 4018 |website=Engineers Edge |access-date=2023-01-24 }}

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|+ Sizes in mm

!ISO 262 sizes

!Internal hex
cap head

!Internal hex
button head

!Internal hex
flat head screws

!Internal hex
set screws

!External hex
ISO standard

!External hex
DIN standard

M2.5

|2.0

|

|

|2.0

|5

|5

M3

|2.5

|2.0

|2.0

|2.0

|5.5

|5.5

M4

|3.0

|2.5

|2.5

|2.5

|7

|7

M5

|4.0

|3.0

|3.0

|3.0

|8

|8

M6

|5.0

|4.0

|4.0

|3.5

|10

|10

M8

|6.0

|5.0

|5.0

|5.0

|13

|13

M10

|8.0

|6.0

|6.0

|6.0

|16

|17

M12

|10.0

|8.0

|8.0

|8.0

|18

|19

M16

|14.0

|10.0

|10.0

|10.0

|24

|24

M20

|17.0

|

|12.0

|12.0

|30

|30

M24

|19.0

|

|

|

|36

|36

M30

|22.0

|

|

|

|46

|46

For Torx bolts, there is a corresponding size driver prescribed by Acument, the designer of the Torx drive system. {{As of|2018}}, there are no ISO standards for hexalobular drive sizes.{{Cite web|url=https://www.acument.com/pdfs/torx_ds.pdf|title=Torx Drive System}}

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! ISO 262 sizes

!Pan head

!Flat head

!Socket head

!Socket Button

!Truss

!External Torx

M2.5

|T8

|T8

|T8

|

|

|

M3

|T10

|T10

|T10

|T8

|

|E4

M4

|T20

|T20

|T25

|T15

|T15

|E5

M5

|T25

|T25

|T27

|T25

|T20

|E6

M6

|T30

|T30

|T30

|T27

|T30

|E8

M8

|T40

|T40

|T45

|T40

|T40

|E10

M10

|T50

|T50

|T50

|T45

|T50

|E12

M12

|

|

|T55

|T55

|T55

|E14

M16

|

|

|T70

|T60

|

|E20

M20

|

|

|T90

|

|

|E24

M24

|

|

|T100

|

|

|E32

M30

|

|

|

|

|

|E36

Similarly, for Torx Plus bolts, there is a corresponding size driver prescribed by Acument, the designer of the Torx Plus drive system. {{As of|2018}}, there are no ISO standards for hexalobular drive sizes.{{Cite web|url=http://www.stanleyengineeredfastening.com/sites/www.emhartamericas.com/files/downloads/Torx_Plus_Brochure_EN.pdf|title=Torx Plus Drive System}}

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!ISO 262 sizes

!Pan head

!Flat head

!Socket head

!Socket Button

!Truss

!External Torx

M2.5

|8IP

|8IP

|8IP

|

|

|4EP

M3

|10IP

|10IP

|10IP

|8IP

|

|5EP

M4

|20IP

|15IP

|20IP

|15IP

|15IP

|7EP

M5

|25IP

|20IP

|27IP

|25IP

|20IP

|8EP

M6

|30IP

|27IP

|30IP

|27IP

|30IP

|10EP

M8

|45IP

|30IP

|45IP

|40IP

|40IP

|14EP

M10

|50IP

|50IP

|50IP

|45IP

|50IP

|16EP

M12

|55IP

|55IP

|55IP

|55IP

|55IP

|20EP

M16

|

|

|70IP

|60IP

|

|26EP

M20

|

|

|90IP

|

|

|32EP

M24

|

|

|100IP

|

|

|40EP

M30

|

|

|

|

|

|

= ISO 1307 plastic hose sizes =

File:Garden hose pistol.JPG

See also:

ISO 1307:2006, Rubber and plastics hoses—Hose sizes, minimum and maximum inside diameters, and tolerances on cut-to-length hoses specifies nominal diameters for four different types of plastic hoses, including "Type C", which includes the typical garden hose. Each nominal diameter specifies different ID minimum and maximum values. The nominal size is a Renard series.

class="wikitable" style=text-align:center;

!Nominal Size

ID

! colspan="2" |Type C

Non-mandrel-built

ID range

!Inch

equivalent

ID

!min

!max

!

3.2

|n/a

|n/a

|

4

|3.4

|4.6

|

5

|4.2

|5.4

|

6.3

|5.6

|7.2

|{{frac|1|8}} in

8

|7.2

|8.8

|{{frac|1|4}} in

10

|8.7

|10.3

|{{frac|3|8}} in

12.5

|11.9

|13.5

|{{frac|1|2}} in

16

|15.1

|16.7

|{{frac|5|8}} in

19

|18.3

|19.9

|{{frac|3|4}} in

20

|19.3

|20.9

|

25

|24.2

|26.6

|1 in

31.5

|30.2

|33.4

|{{frac|1|1|4}} in

38

|36.5

|39.7

|{{frac|1|1|2}} in

= ISO 6708 nominal pipe diameter =

{{Anchor|ISO 6708}}

File:Butterfly-valve--The-Alloy-Valve-Stockist.JPG in a large DN-size.]]

Nominal diameter, abbreviated DN (diamètre nominal/Durchmesser nach Norm), is the designation system specified by ISO 6708 for specifying the diameter of trade sizes of metric pipework components, and is the metric equivalent to Nominal Pipe Size.{{Cite web|url=https://www.iso.org/standard/21274.html|title=ISO 6708:1995: Pipework components -- Definition and selection of DN (nominal size)|access-date=2017-10-13}} It is among several ISO specifications that formalize preferred numbers, and is referred to by numerous other international standards, including ISO 7598 and EN 10255. The complete set of DN values allowed by the standard are:

class="wikitable" style=text-align:center;

!DN designation

!DN designation

!DN designation

DN 10

|DN 250

|DN 1 500

DN 15

|DN 300

|DN 1 600

DN 20

|DN 350

|DN 1 800

DN 25

|DN 400

|DN 2 000

DN 32

|DN 450

|DN 2 200

DN 40

|DN 500

|DN 2 400

DN 50

|DN 600

|DN 2 600

DN 60

|DN 700

|DN 2 800

DN 65

|DN 800

|DN 3000

DN 80

|DN 900

|DN 3200

DN 100

|DN 1 000

|DN 3 400

DN 125

|DN 1 100

|DN 3 600

DN 150

|DN 1 200

|DN 3 800

DN 200

|DN 1 400

|DN 4 000

The number following the DN is a nominal value that is roughly the number of millimeters of a circular feature on the connection point of the pipe, fitting, coupling, etc., but often differing by a noticeable amount. If the DN value is related to the internal bore diameter of the feature, the size should be represented by DN/ID (for Inside Diameter), and if the DN value is related to the outside diameter, the size should be represented by DN/OD (for Outside Diameter).

The relationship between DN and NPS pipe sizes are as follows. Note that the actual internal diameter varies depending on the pipe wall thickness.{{Cite web|url=http://www.wes.ir/files/797832605piptub.pdf|title=Tube Sizes - ISO|access-date=2017-10-13}}

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!DN

!Actual OD

!NPS{{Cite web|url=https://www.iso.org/standard/31327.html|title=ISO 17292:2004, Metal ball valves for petroleum, petrochemical and allied industries|access-date=2017-10-16}}

designation

!mm

!designation

DN 10

|17.2

|{{Frac|3|8}}

DN 15

|21.3

|{{Frac|1|2}}

DN 20

|26.9

|{{Frac|3|4}}

DN 25

|33.7

|1

DN 32

|42.4

|{{Frac|1|1|4}}

DN 40

|48.3

|{{Frac|1|1|2}}

DN 50

|60.3

|2

DN 65

|76.1

|{{Frac|2|1|2}}

DN 80

|88.9

|3

DN 100

|114.3

|4

DN 125

|139.7

| -

DN 150

|168.3

|6

DN 200

|219.1

|8

DN 250

|273

|10

DN 300

|323.9

|12

DN 350

|355.6

|14

DN 400

|406.4

|16

DN 450

|457

|18

DN 500

|508

|20

DN 600

|610

|24

DN 700

|711

|28

DN 750

|762

|32

DN 800

|813

|34

DN 900

|914

|36

DN 1 000

|1016

|40

DN 1 200

|1220

|48

See also

  • Adjustable shelving, used in logistics with items and carriers of various standardised and non-standardised sizes
  • Eurocontainer, a system for boxes that can be used for reusable packaging for transport and storage
  • Gastronorm, a standard for professional kitchenware tray and container sizes
  • ISO metric screw thread, the international standard for machine screw threads

References