by: mr. lua. alphabet of lines when viewing mechanical drawings you will find several lines. this is...
DESCRIPTION
Construction and Guide Lines Construction Used to lay out drawings. Guide Used usually when lettering to create the information boxes.TRANSCRIPT
Drafting BackgroundBy: Mr. Lua
Alphabet of LinesWhen viewing mechanical drawings you will
find several lines.This is simply reference system used to
remember different types of lines.Will focus on 10 specific most common ones.
Construction and Guide LinesConstruction
Used to lay out drawings. Guide
Used usually when lettering to create the information boxes.
Border LineIs the heaviest or thickest line used in
sketching.
Object LinesThick line but slightly less thick than a
boarder line. This line indicates the visible edges of the part.
Hidden LinesAre used to show the hidden features of a
part.Dashes of (1/8 in) and (1/16 in)
Extension LineThese are as think as dimension lines and
indicate points from which the dimensions are taken.
Dimension LineGenerally ends with an arrowhead at the
ends. Usually placed between two extension lines,
with a break usually at the center to place the dimension value.
CenterlineMade of alternate long and short dashes with
spaces between them.Long (3/4 in to 1 1/12 in)Short (1/8 in)Dashes (1/16 in)
Cutting-Plane LinesIndicates where an obeject has been cut to
show interior features. Two types used:
1/4 in dashes with 1/16 in spacing A long dash (3/4 in to 1 1/2 in) then two short
dashes (1/8 in) and spacing of 1/16 in
Section LineUsed when drawing inside features of an
object to indicate the surfaces exposed by the cutting-plane line.
Phantom LineUsed to show alternating positions of a
moving part, repeated details or the path of motion of an object.Consists of:
Dashes (3/4 in to 1 1/2 in) separated by two short lines of 1/8 in