A scale ruler is a tool for measuring lengths and transferring measurements at a fixed

ratio In mathematics, a ratio () shows how many times one number contains another. For example, if there are eight oranges and six lemons in a bowl of fruit, then the ratio of oranges to lemons is eight to six (that is, 8:6, which is equivalent to the ...

of length; two common examples are an architect's scale and engineer's scale. In scientific and engineering terminology, a device to measure linear distance and create proportional linear measurements is called a scale. A device for drawing straight lines is a straight edge or

ruler A ruler, sometimes called a rule, scale, line gauge, or metre/meter stick, is an instrument used to make length measurements, whereby a length is read from a series of markings called "rules" along an edge of the device. Usually, the instr ...

. In common usage, both are referred to as a ruler.

Architect's scale

An architect's scale is a specialized

designed to facilitate the drafting and measuring of

architectural drawing An architectural drawing or architect's drawing is a technical drawing of a building (or building project) that falls within the definition of architecture. Architectural drawings are used by architects and others for a number of purposes: to deve ...

s, such as

floor plan In architecture and building engineering, a floor plan is a technical drawing to scale, showing a view from above, of the relationships between rooms, spaces, traffic patterns, and other physical features at one level of a structure. Dimensio ...

s and Multi-view orthographic projections. Because the scale of such drawings is often smaller than life-size, an architect's scale features multiple

units of length A unit of length refers to any arbitrarily chosen and accepted reference standard for measurement of length. The most common units in modern use are the metric system, metric units, used in every country globally. In the United States the U.S. ...

and proportional length increments. For accuracy and longevity, the material used should be dimensionally stable and durable. Scales were traditionally made of wood, but today they are usually made of rigid

plastic Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

United States and Imperial units

In the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and prior to

metrication Metrication or metrification is the act or process of converting to the metric system of measurement. All over the world, countries have transitioned from local and traditional Unit of measurement, units of measurement to the metric system. This ...

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and

Australasia Australasia is a subregion of Oceania, comprising Australia, New Zealand (overlapping with Polynesia), and sometimes including New Guinea and surrounding islands (overlapping with Melanesia). The term is used in a number of different context ...

, architect's scales are marked as a ratio of x

inch The inch (symbol: in or prime (symbol), ) is a Units of measurement, unit of length in the imperial units, British Imperial and the United States customary units, United States customary System of measurement, systems of measurement. It is eq ...

es-to-the-

foot The foot (: feet) is an anatomical structure found in many vertebrates. It is the terminal portion of a limb which bears weight and allows locomotion. In many animals with feet, the foot is an organ at the terminal part of the leg made up o ...

(typically written as ''x''″=1′-0″). For example, one inch measured from a drawing with a scale of "one-inch-to-the-foot" is equivalent to one foot in the real world (a scale of 1:12)....one inch measured from a drawing with a scale of "two-inches-to-the-foot" is equivalent to six inches in the real world (a scale of 1:6). It is not to be confused with a true unitless ratio. A 1:5 architectural scale (inches to feet) would be a 1:60 unitless scale (inches to inches) since there are 60 inches in 5 feet. Typical scales used in the United States are: : full scale, with inches, divided into sixteenths of an inch The following scales are generally grouped in pairs using the same dual-numbered index line (one scale is read from the right, and the other scale is read from the left): :

Metric units

Architect's scale rulers used in Britain and other

metric Metric or metrical may refer to: Measuring * Metric system, an internationally adopted decimal system of measurement * An adjective indicating relation to measurement in general, or a noun describing a specific type of measurement Mathematics ...

countries are marked with

s without reference to a base unit. Therefore, a drawing will indicate both its scale (ratio) and the unit of measurement being used. In Britain, and elsewhere, the standard units used on architectural drawings are the (SI) units

millimetre 330px, Different lengths as in respect of the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 metre to 1 millimetre. The millimetre (American and British English spelling differences#-re, -er, i ...

s (mm) and

metre The metre (or meter in US spelling; symbol: m) is the base unit of length in the International System of Units (SI). Since 2019, the metre has been defined as the length of the path travelled by light in vacuum during a time interval of of ...

s (m), whereas in France

centimetre upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter. A centimetre (International spelling) or centimeter (American ...

s (cm) and metres are most often used. In Britain, for flat rulers, the paired scales often found on architect's scales are: *1:1/1:10 *1:5/1:50 *1:10/1:100 *1:20/1:200 *1:1250/1:2500 For triangular rulers, the paired scales are: *1:1/1:10 *1:2/1:20 *1:5/1:50 *1:100/1:200 *1:500/1:1000 *1:1250/1:2500 Less common scales are: *1:25/1:250 *1:33 *2:1 In France, in engineering departments or architectural offices, here are some scales used : * 1:100 / 1:300 * 1:200 / 1:400 * 1:250 / 1:500

Engineer's scale

An engineer's scale is a tool for measuring distances and transferring measurements at a fixed

of length. It is commonly made of

or aluminum and is just over long, but with the only 300 mm of markings, leaving the ends unmarked so that the first and last measuring ticks do not wear off. It is used in making engineering drawings, commonly called

blueprint A blueprint is a reproduction of a technical drawing or engineering drawing using a contact print process on light-sensitive sheets introduced by Sir John Herschel in 1842. The process allowed rapid and accurate production of an unlimited number ...

s, blue lines, or plans on a specific scale. For example, "one-tenth size" would appear on a drawing to indicate a part larger than the drawing on the paper itself. It is not to be used to measure machined parts to see if they meet specifications. In the

this scale is divided into decimalized fractions of an

but has a cross-section like an equilateral triangle, which enables the scale to have six edges indexed for measurement. One edge is divided into tenths of an inch, and the subsequent ones are directly marked for twentieths, thirtieths, fortieths, fiftieths, and finally sixtieths of an inch. Referred to as 1:10, 1:20, 1:30,1:40, 1:50 or 1:60 scale. Typically in civil engineering applications, 1:10 (1″=10′) is used exclusively for detail drawings. 1:20 and 1:40 scales are used for working plans. 1:60 is normally used only to show large areas of a project. In 1918 French described the US engineer's scale using the term "civil engineers' scale", and it was said to be "used for plotting and map drawing, and the graphic solution of problems."

References

External links