Beginning in the second half of the 18th century in England, the industrial revolution in the 19th century swept through many countries of Europe and the world. It was characterized by the rapid development of technology and industrial production. The manufacture of products moved from manufactories and workshops to large factories. However, the transition from single and small-scale production to mass production, as well as the division of labor, required the creation of a variety of design and technological documentation, which led to the development of applied discipline - drawing.
The advent of standardization
Drawing allows you to create a graphic image of the object necessary for its manufacture. However, for the production of one appearance of the product is not enough. The drawing also contains the dimensions, scale, technical requirements, material and other characteristics of the part. Further development of production led to the division of labor, when components are manufactured at different enterprises, and then the finished product is assembled. This required the unification and standardization of parts and a single rule for the execution of drawings. For the convenience of recording and perceiving technical information, conventions were introduced, such as, for example, a sign of diameter or thickness, facilitating the recording of indicated characteristics.
Legend: diameter sign
The standards provide various conventions that allow you to record the geometric and technological parameters of the depicted object: signs of radius, thickness, angle, tolerance and machining allowance. The diameter also refers to them, which determines the dimensions of the holes and bodies of revolution. A chord connecting two points on a circle (ball) and passing through its (his) center is called a diameter. How is it indicated in the drawings? The sign of the diameter is a circle crossed out by a line inclined at 45
° to the vertical in the clockwise direction. In some cases, the Latin letter D is used, which is allowed to be used along with the main character.
Word Diameter Sign
With the development of computer technology, most of the design documentation began to be converted into electronic form, which facilitates the creation, storage, forwarding and duplication of drawings and technological maps. For this, special programs are used. For example, AutoCAD is used to build drawings, and Word, which is part of the Microsoft Office suite, is used for text documents. Along with paid software, there is also free: NanoCAD, Open Office.
Accordingly, the legend, including the sign of the diameter, migrated to these programs. It is absent on the standard keyboard layout, therefore, to insert it into a document created using a Word text editor, you must go the following way: “Insert → Symbol → Other symbols → switch“ Font ”to“ Symbol ”→ Æ". The code for the diameter sign in "Symbol (hexadecimal)" is 006. Since this element is not present in all fonts, it can be replaced by a crossed-out “o”: “Ø”, code - 00D8 in “Unicode (16)”.