Diagrams and drawings are considered business, design documentation, so their design must comply with standard requirements. Especially strict adherence to them is necessary in the manufacture of drawings, where the accuracy of applying graphic design elements to paper is measured in fractions of a millimeter.
Design elements for diagrams and drawings are scales, frames, stamp, sheet formats, inscriptions and numbers, the font used and its dimensions. A whole package of state industry standards (GOSTs) has been developed, which is called the "Unified System for Design Documentation" (ESKD). In it you can find regulations for the design of any graphic element of a drawing or diagram, including the images themselves, as well as designations, used fonts, inscriptions, tables.
To facilitate the storage of drawings and diagrams, they should be made on sheets of fixed dimensions, which are called formats. The larger format is derived from the smaller format sheet. So, a standard sheet of paper has an A4 format, its length is 21 mm, its height is 297 mm, the A3 format is equal to two A4 sheets, the A2 format is equal to two A3 sheets and four A4 sheets, etc. Each of the larger sizes can thus be folded down to A4 size.
In addition to the fixed sheet size, special requirements are imposed on the design of the frame, stamp and out-of-frame inscriptions of a drawing or diagram. The left margin of the frame is 20 mm, it is intended for filing this document. All other margins of the frame are 5 mm. But the frame itself must have a certain line thickness - 0.5 mm. The main image of a part or other graphic elements is made using lines of different thickness, which depends on the type - main, auxiliary, etc. In drawings and diagrams, lines with a thickness of 0.5 to 1.4 mm are used.
There is always a stamp in the lower right corner of the drawing. This is a table with margins of various heights and widths, also fixed. In certain fields, inscriptions are placed with the name of the part or diagram, its scale, the number of sheets, the contractor, the official who checked it, etc. The total height of the stamp is 55 mm, its width is always 185 mm.
General rules for the design of drawings and diagrams are contained in GOST 2.307-68. It also indicates the size of the fonts used for inscriptions and symbols. In drawings and diagrams, all numbers and letters are written in one font, which is called “drawing”. Study his sample and practice writing before you draw up the document itself.