Engineering Drawing II
(Descriptive Geometry)
Standard drafting practices for labeling points, lines, and planes
Lettering:
All points, lines, and planes should be labeled using 1/8" high letters with guidelines. Lines should be
labeled at each end and planes at each corner. Either letters or numbers can be used for labeling.
Points:
Points in space should be indicated by two short dashes that are perpendicular to form a cross. Dots are
never used to represent a point. Each dash should be approximately 1/8" long.
Points on a line:
Points on a line should be indicated with a short perpendicular dash on the line. Dots are never used to
represent a point on a line. Label the point with a letter or numeral.
Construction lines and projection lines:
Projection lines are lines that are used in constructing the solution to a problem. Construction lines and
projection lines are drawn as very thin, light lines. Construction lines should not be erased on descriptive
geometry problems so that the drawing solutions can be checked and verified.
Reference lines and Fold lines:
Reference lines and fold lines are thin black lines that are labeled in accordance with the textbook.
Object lines:
Object lines used to represent points, lines, and planes should be drawn as thick, dense black lines.
Hidden lines:
Hidden lines are drawn as thin, dense black lines. Dashes in a hidden should be 1/8" long with a spacing
of 1/16".
Center lines:
Center lines are drawn as thin, dense black lines.
Engineering Drawing II
(Descriptive Geometry)
True length lines:
True length lines should be label by the full note TRUE LENGTH or by the abbreviation TL.
TL
True size planes:
True size planes should be labeled by the full note TRUE SIZE or by the abbreviation TS.
Marking piercing points and showing visibility:
Piercing points are marked with a dash at the point of penetration. Piercing points are not labeled unless
required in the directions for a specific problem or application. Visibility is shown using conventional
hidden lines and visible object lines. Note that the hidden line rules for intersecting dashes is followed.
CAD Drawings
Description
Center Lines
Construction lines
Fold Lines
Hidden Lines
Object lines
Text/Dimension
Title Block
Layer Name
Center Lines
Construction
Fold Lines
Hidden Lines
Object Lines
Text
Title block
Color
White (7)
252
252
White (7)
White (7)
White (7)
White (7)
Linetype
Continuous
Continuous
Continuous
Hidden2
Continuous
Continuous
Continuous
Lineweight
Default 0.010
Default 0.010
Default 0.010
Default 0.010
0.020
Default 0.010
Default 0.010
All drawing components should be placed on the appropriate layers. Set the Plot Style Table to Grayscale
for plotting. Construction lines and fold lines should be plotted as light, thin lines.
2