According to the national standard, the drawing frame must be drawn with thick solid lines, with or without binding edges, but only one format can be used for drawing the same product. For drawings with or without binding edges, the frame format is shown in the figure below, and the frame size is shown in the figure below:
On the left is the reserved binding edge, and on the right is the schematic diagram of the drawing frame without binding edge.
See the above table for the frame format.
Extended data:
In order to facilitate the management and exchange of drawings, the State Bureau of Technical Supervision issued the national standards for technical drawings and mechanical drawings, which made a series of unified regulations on drawings.
In order to facilitate binding and management, make the drawing size uniform, and meet the requirements of miniature reproduction of the original, national standards stipulate that when drawing technical drawings, they should be drawn on drawings with certain formats (A0, A 1, A2, A3, A4), and basic drawings are preferred.
When drawing a drawing, the basic format size of the drawing specified in table 1 should be adopted, and the size unit is millimeters ... There are five basic format codes: A0, A 1, A2, A3 and A4. The ratio of the long side to the short side of drawings with various drawing numbers is the same, which is1.414213562, which is the square root of 2. In other words, if the drawings are poor, the area will be poor.
By analogy, the length of the small picture is equal to the width of the big picture, and the width of the small picture is equal to half the length of the big picture (approximate, consider rounding).
References:
Baidu Encyclopedia-Drawing Format