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2.5 CONVENTION AND SIMPLIFICATION AT THE CONSTRUCTION OF IMAGES

State Standard 2.305—68 recommends to apply some conventions and simplification at
implementation of different images of object.
1- If an image is a symmetric figure, it is possible to draw the half of image or slightly more
halves of depiction only, limiting to his axial or wavy line (fig. 2.27, a).
2 – If a few identical, evenly placed elements have an object, dark-and-light this object fully
show one or two such the element, and other – simplified or de bene esse (fig.2.27, b);
3 – It is also possible to represent part of object, specifying the amount of elements, their
location and others like that (fig.2.27, c);
4 – Rivets, bolts, nuts, keys, etc. are not sectioned. It is a convention in machine drawing that
shafts, nuts, bolts, screw and all other threaded parts, keys, cotters and other simple fastening
devices, spokes, ribs, webs are not sectioned. Therefore only a small portion of the sectioned object
is shown with hatched lines. Thin walls do not shade the spoke of fly-wheels, pulleys, gear-wheels,
rib of inflexibility, if a cutting plane is placed along the ax of such element (fig.2.27, d).

Figure 2.27 – Conventions and simplification

5 – The smooth transition from one surface to other is represented conventionally or not
nearly represented (fig. 2.28, a);;
6 – It can be allowed simplifications, analogical to mentioned on a picture (fig.2.28, b);
7 – It can be allowed to represent insignificant taper or slope with an increase (fig.2.28, c);
8 - Details which have large length, permanent crossrunner or such, that changes
appropriately, it is possible to show with a break (fig.2.28, d);

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