2, H pencil: write in the picture; ?

3.2H Pencil: Draw thin solid line, center line, dimension line, double-dot dash line, section line, etc. ?

4, 3H pencil: drawing.

Extended materials:

1, mechanical drawing line width regulation?

Mechanical drawing stipulates that the line width (D) of all line types should be selected from the following series according to the type and size of patterns:? 0. 13mm； 0. 18mm； 0.25mm0.35mm0.5mm0.7mm 1.0mm； 1.4mm； 2.0mm？

The width d of thick solid line can be selected between 0.5~2mm (generally used in practice), and the width of thin line is d/2.

2, the choice of line width

(1) "The number of fonts, that is, the height h of fonts, can be divided into eight types: 20, 14,/kloc-0, 7, 5, 3.5, 2.5,1.8 mm"-"Mechanical Drawing" (No. ;

(2) "There are two types of letters and numbers: A type and B type, and B type font is recommended. The stroke width (d) of type B font is110 of the word height (h). " -Mechanical Drawing (4th Edition) P8;

(3) "The line widths d of all line types are selected from the series of 0. 13, 0. 18, 0.25, 0.35, 0.5, 0.7, 1, 1.4 and 2mm according to the types and sizes of patterns." -mechanical drawing (4th edition) P 10? "The height of Chinese characters should not be less than 3.5mm" —— Mechanical Drawing (5th Edition) P7? ;

(4) "In mechanical drawing, two kinds of line widths are usually adopted, the ratio of thick line to thin line is 2: 1, and the width of thick line is preferably 0.5 mm and 0.7 mm. In order to ensure clear patterns and easy reproduction, lines with line widths less than 0. 18 mm should be avoided as far as possible"-Mechanical Drawing (5th Edition) p . ?

Based on the above point of view, the following 7 pairs of optional thick and thin line widths are obtained:?

a.0. 13:0.25、b.0. 18:0.35、c.0.25:0.5、d.0.35:0.7、e.0.5: 1、f.0.7: 1.4、g. 1:2？ ;

3, collocation, font size, line width, evaluation, reason, thin line, thick line

( 1)? 0. 13? 0.25? Neither manual drawing nor computer drawing is recommended. First, there is no corresponding font size; Second, the line width of thin lines is too small; ?

(2) 1.8? 0. 18? 0.35? Neither manual drawing nor computer drawing is recommended. First, the font size is less than 3.5; Second, the line width of thin lines just reaches the minimum recommended value 1.8mm, and Chinese characters will be unclear; ?

(3)2.5? 0.25? 0.5? It is recommended to use AutoCAD. If the font is less than 3.5, the Chinese characters will be unclear, and manual drawing is not recommended. ?

4. When drawing by computer, the default configuration of AutoCAD line width is 0.25, 0.25 is fine line width and 0.5 is coarse line width, which is just one of the recommended coarse line widths. Therefore, it is recommended to use this configuration in AutoCAD (for unified examination and normal drawing).

It is estimated that this is also the meaning of 0.5mm recommended by P 10 in Mechanical Drawing (5th Edition). ?

( 1)3.5? 0.35? 0.7? Suggest drawing by hand (pencil drawing)? The font size of this collocation is the recommended minimum Chinese font size of 3.5, so this collocation actually becomes the "minimum collocation" allowed by manual drawing, and the drawing we are currently making is usually the smallest A4 drawing.

Of course, the smallest font size is chosen, so this collocation is often used in school manual drawing. It is estimated that this is also the meaning of 0.7mm recommended by P 10 in Mechanical Drawing (5th Edition). ?

(2)5? 0.5? 1? Is it recommended to draw by hand (automatic pencil drawing)? Choose 0.5 and 1 for manual drawing, because it is recommended to use movable pencils for manual drawing, and 0.5 and 1mm refills are easier to find. ?

f？ 7? 0.7? 1.4? Neither manual drawing nor computer drawing is recommended. g？ 10? 1? 2? Neither manual drawing nor computer drawing is recommended.

5. Conclusion:?

The line widths of (1) thick/thin lines can be 2: 1, 1.4:0.7, 1:0.5 and 0.7:0.35.

At present, the A4 drawing with the most contact is the smallest drawing. If the font size is the minimum recommended value of 3.5#, then the corresponding thickness and line width collocation is 0.7:0.35, which is the most qualified collocation and recommended by many teachers.

However, in manual drawing, it is strongly recommended that you draw with a mechanical pencil. In order to facilitate the purchase of pencil lead, it is also allowed to choose the pen width of 1 and 0.5 for manual drawing, but it is a little too big; ?

(2) 2) The default line width setting of AutoCAD is 0.25mm Many people are used to this setting. cg animation is usually drawn by a printer, so it doesn't matter if the line width is a little thinner.

Therefore, line widths of 0.5 and 0.25 are adopted. According to the national standard, this line width corresponds to 2.5#, which is smaller than the recommended minimum font size of 3.5#, but it can be seen when printing, so this is adopted.

References:

Baidu encyclopedia-mechanical drawing