CONVENTIONAL DRAWING OF FIXINGS AND JOINTS
SCREW JOINT
The thickness of an overhead joining part and parameters of a screw are input data for the drawing of a screw joint. At the structural drawing of a screw joint (fig. 4.24, а, b, c) it is necessary to draw all structural elements of parts. The sizes of a thread, length of a screw and sizes of a base surface under a head fill in. A slot under a screwdriver is disposed under the corner 45° at the view from the face head. On the simplified drawing of a screw joint (fig. 4.24, d, e, f) the sizes of a thread and a length of a screw are marked. A slot under a screwdriver is represented an incrassate contour line. The thread opening under a screw is drawn like an opening under a stud.
а) b) c) d) e) f)
Figure 4.24 – The screw joint
The parameters of a base surface under a head of screw are regulated by State Standard 12876:2008.
The conventional drawing of fixings (table 4.11) is regulated by State Standard 2.315:2008. Fixings for which on a drawing the diameter of a bar is equal 2 mm or less is shown conventionally. Conventional drawing and its sizes must give exhaustive and necessary information about the view of a joint and its components.
Table 4.11 - The conventional drawing of fixings
Name of a part | View | Drawing | Name of a part | View | Drawing |
Round-head and cheese-head bolts and screws | Main (front) | Nuts | Main (front) | ||
Top | Top | ||||
Bottom | · | Washers | Main (front) | ||
Countersunk-head and oval-head screws | Main (front) | Top | |||
Top | Studs | Main (front) | |||
Bottom | · | Top | · |
In fig.4.25 the examples of conventional drawings of thread joints are resulted: a – by a bolt on a view and in a section; b – by a stud on a view and in a section; c – by a countersunk-head screw on a view and in a section; d –by a cheese-head screw on a view and in a section.
а) b) c) d)
Figure 4.25 – Conventional drawings of thread joints