Preferred metric sizes are a set of

international standard international standard is a technical standard developed by one or more international standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization is the International Or ...

s and

de facto standard A ''de facto'' standard is a custom or convention that has achieved a dominant position by public acceptance or market forces (for example, by early entrance to the market). is a Latin phrase (literally " in fact"), here meaning "in practice b ...

s 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 In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints. Product developers must choose numerous lengths, distanc ...

and convenient numbers such as the

Renard series Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in ...

, the 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, specify the capacities of liquor bottles allowed in international commerce as the following 10 sizes: * 100 ml ( L) * 250 ml ( L) * 375 ml ( L) * 500 ml ( L) * 750 ml ( 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: * 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

See Also: * ISO 6708 Nominal Diameter (for garden hose sizes)

System 32 furniture

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

The

ISO 2848 ISO 2848 (''Building construction – Modular coordination – Principles and rules)'' is an international standard for the construction industry that describes the aims of modular coordination and gives the rules to be used in establishing the di ...

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. * 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 ISO 216 is an international standard for paper sizes, used around the world except in North America and parts of Latin America. The standard defines the "A", "B" and "C" series of paper sizes, including A4, the most commonly available paper size ...

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 , 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

ISO 261 defines a set of preferred metric machine screw/bolt sizes, and

ISO 262 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. Th ...

defines a subset of those; both are based roughly on

as defined in

ISO 3 ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...

ISO 17 Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in ...

, and

ISO 497 Renard series are a system of preferred numbers dividing an interval from 1 to 10 into 5, 10, 20, or 40 steps. This set of preferred numbers was proposed in 1877 by French army engineer Colonel Charles Renard. His system was adopted by the ISO in ...

. 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 The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via " continuing ...

and ANSI B4.2, Knut O. Kverneland, to reduce the list to 6 preferred sizes, and another 6 intermediate supplementary sizes. 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 2936:2001 "Assembly tools for screws and nuts—Hexagon socket screw keys" * External hex drive: ISO 4014, 4015, 4015, 4017, and 4018. For each size bolt or screw and type of head, there is a corresponding size driver prescribed by Acument, the designer of the Torx drive system. , there are no ISO standards for hexalobular drive sizes. For each size bolt or screw and type of head, there is a corresponding size driver prescribed by Acument, the designer of the Torx Plus drive system. , there are no ISO standards for hexalobular drive sizes.

ISO 1307 plastic hose sizes

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 A garden hose, hosepipe, or simply hose is a flexible tube used to convey water. There are a number of common attachments available for the end of the hose, such as sprayers and sprinklers (which are used to concentrate water at one point or ...

. Each nominal diameter specifies different ID minimum and maximum values. The nominal size is a

ISO 6708 nominal pipe diameter

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 Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures. "Nominal" refers to pipe in non-specific terms and identifies the diameter of the hole with a non-dimensional number (for ...

. It is among several ISO specifications that formalize

preferred number In industrial design, preferred numbers (also called preferred values or preferred series) are standard guidelines for choosing exact product dimensions within a given set of constraints. Product developers must choose numerous lengths, distance ...

s, 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: The number following the DN is a

nominal value In economics, nominal value is measured in terms of money, whereas real value is measured against goods or services. A real value is one which has been adjusted for inflation, enabling comparison of quantities as if the prices of goods had not c ...

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 NPS may refer to: Organizations * National Park Service, U.S. * National Pension System, India * National Pension Service, Korea * National Phobics Society, UK charity * National Piers Society, UK charity * National Poetry Slam, competition * N ...

pipe sizes are as follows. Note that the actual internal diameter varies depending on the pipe wall thickness. {, class="wikitable" !DN !Actual OD !NPS , - !dimensionless !mm !dimensionless , - , DN 10 , 17.2 , , - , DN 15 , 21.3 , , - , DN 20 , 26.9 , , - , DN 25 , 33.7 , 1 , - , DN 32 , 42.4 , , - , DN 40 , 48.3 , , - , 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

References

* Metric system