Figure 56. The Reference System for Oblique Drawings

Principles of Drafting and Shop Drawnings
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The receding lines may be drawn at any convenient angle. Upward and to the right

at either 30, or 45, are most commonly used because these angles may be drawn with

standard triangles.

The choice of which receding angle to use depends on which

angle best shows the object involved.

Dimensional values are directly transferable from the front view of the

orthographic drawing to the front view of the oblique drawing. Circles transfer as

circles, not as ellipses as in isometric drawings, and angles transfer as the same

angles. Dimensional values in all other views are not directly transferable. They

can only be transferred from the orthographic views to the receding axis of the

oblique drawing.

Sometimes, when dimensional values are transferred to the receding axis of the

oblique drawing, they are redrawn at a reduced scale. The scale reduction improves

the visual quality of the drawing. Note that in figure 57 (on the following page)

the reduced scale of the receding axis changes the way the object looks. Although

any scale reduction may be used, the most common is the half-scale reduction called

a cabinet projection.

If the dimensional values are transferred full-scale, the

resulting oblique drawing is called a cavalier projection.