Engineer's scale
Encyclopedia
Ratio
In mathematics, a ratio is a relationship between two numbers of the same kind , usually expressed as "a to b" or a:b, sometimes expressed arithmetically as a dimensionless quotient of the two which explicitly indicates how many times the first number contains the second In mathematics, a ratio is...
of length. It is commonly made of plastic
Plastic
A plastic material is any of a wide range of synthetic or semi-synthetic organic solids used in the manufacture of industrial products. Plastics are typically polymers of high molecular mass, and may contain other substances to improve performance and/or reduce production costs...
,or aluminum and is just over 12 inches (305 mm) long, but with only 12 inches 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
Blueprint
A blueprint is a type of paper-based reproduction usually of a technical drawing, documenting an architecture or an engineering design. More generally, the term "blueprint" has come to be used to refer to any detailed plan....
s, blue lines or plans in 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 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
Ruler
A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing and engineering/building to measure distances and/or to rule straight lines...
. In common usage both are referred to as a ruler.
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, this scale is divided into decimalized fractions of an inch
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
, 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.
The engineer's scale came into existence when machining parts required a greater precision than the usual, binary fractionalization of the inch as in the architect's scale
Architect's scale
An architect's scale is a specialized ruler designed to facilitate the drafting and measuring of architectural drawings, such as floor plans and orthographic projections...
for houses and furniture. They were used, for example, in laying out printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s with the spacing of leads
Lead (electronics)
In electronics, a lead is an electrical connection consisting of a length of wire or soldering pad that comes from a device. Leads are used for physical support, to transfer power, to probe circuits , and to transmit information...
from integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s as one-tenth of an inch.
On the other hand, they may have come into existence far earlier for use in civil engineering applications when project scope could far exceed the potential of an architect's scale.
See also
- Imperial units
- Linear scaleLinear scaleA linear scale, also called a bar scale, scale bar, graphic scale, or graphical scale, is a means of visually showing the scale of a map, nautical chart, engineering drawing, or architectural drawing....
- Metric scale
- Metric systemMetric systemThe metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
- Scale (map)Scale (map)The scale of a map is defined as the ratio of a distance on the map to the corresponding distance on the ground.If the region of the map is small enough for the curvature of the Earth to be neglected, then the scale may be taken as a constant ratio over the whole map....
- Customary unitsUnited States customary unitsUnited States customary units are a system of measurements commonly used in the United States. Many U.S. units are virtually identical to their imperial counterparts, but the U.S. customary system developed from English units used in the British Empire before the system of imperial units was...
- Units of measurementUnits of measurementA unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...