2D DRAWING REPRESENTATION
COMMON MANUFACTURED FEATURES
Fillet: A rounded interior blend between
surfaces; used, for example, to strengthen
adjoining surfaces.
Round
Fillet
Round: A rounded exterior blend between
surfaces; used to make edges and corners
easier to handle, improve strength of
castings.
Common Hole Features Shown in Orthographic Views
COMMON MANUFACTURED FEATURES
Counterbore : A cylindrical recess around a
hole, usually to receive a bolt head or nut.
Counterbore
COMMON MANUFACTURED FEATURES
Countersink : A cone-shaped recess
around a hole, often used to receive a
tapered screw head.
Countersink
Common Hole Features Shown in Orthographic Views
COMMON MANUFACTURED FEATURES
Spotface: A shallow recess like a
counterbore, used to provide a good
bearing surface for a fastener.
Spotface
COMMON MANUFACTURED FEATURES
Boss: A short raised protrusion above the
surface of a part, often used to provide a
strong flat bearing surface
Boss
COMMON MANUFACTURED FEATURES
Lug : A flat or rounded tab protruding from
a surface, usually to provide a method for
attachment.
Lug
Flange
Flange: A flattened collar or rim around a
cylindrical part to allow for attachment
COMMON MANUFACTURED FEATURES
Chamfer: An angled surface, used on a
cylinder to make it easier to start into a
hole, or a plate to make it easier to handle
Chamfer
Neck
Neck: A small groove cut around the
diameter of a cylinder, often where it
changes diameter
COMMON MANUFACTURED FEATURES
Keyway/Keyseat: A shaped depression cut
along the axis of a cylinder or hub to
receive a key, used to attach hubs, gears,
and other parts to a cylinder so they will
not turn on it
Keyway
Knurl
Knurl: A pattern on a surface to provide for
better gripping or more surface area for
attachment, often used on knobs and tool
handles
Common Features Shown in Orthographic Views
Common Features Shown in Orthographic Views
COMMON MANUFACTURED FEATURES
Bushing: A hollow cylinder that is often
used as a protective sleeve or guide, or as
a bearing
VISUALIZING AND DRAWING COMPLE CYLINDRICAL SHAPES
How to visualize cylindrical features being cut from a rectangular block (prism).
• The top view appears as a rectangle.
• The center-line for the rounded top is
shown in all three views.
• Only one view is required.
VISUALIZING AND DRAWING COMPLE CYLINDRICAL SHAPES
• The material for the center
hole is removed.
• Hidden lines are added to
the top and side view .
• In the front view the hole
appears round.
• The centerlines in the
drawing locate the hole.
• Only one view is required.
VISUALIZING AND DRAWING COMPLE CYLINDRICAL SHAPES
• The counterbored holes are created.
• The side view or top view or a note
specifying the depth of the
counterbore is needed.
VISUALIZING AND DRAWING COMPLE CYLINDRICAL SHAPES
A portion of the top surface is removed. Notice how those line appear
in the top and side views.
The top or side view or a note is
required.
The side view is probably a
better choice, because it shows
more about the shape than the
top view.
INTERSECTIONS AND TANGENCIES
When a plane surface intersects the contoured surface, a line is drawn to
represent the edge formed by that intersection.
INTERSECTIONS AND TANGENCIES
When the plane surface is tangent to the contoured surface, no line is drawn
where the surfaces meet.
INTERSECTIONS AND TANGENCIES
a. Where a curved surface is tangent to a plane surface no line is drawn.
b. When it intersects a plane surface, a definite edge is formed.
c. When curves join each other or plane surfaces smoothly a line is not drawn
to show where they come together.
d. If a combination of curves creates a vertical surface, the vertical surface is
shown as a line.
INTERSECTIONS AND TANGENCIES
When plane surfaces join a contoured surface, a line is not shown if they are
tangent, but is shown if they intersect.
INTERSECTIONS OF CYLINDERS
• When the intersection is small, its curved
shape is not plotted accurately because it
adds little to the sketch or drawing for the
time it takes.
• Instead it is shown as a straight line.
INTERSECTIONS OF CYLINDERS
• When the intersection is larger, it can be
approximated by drawing an arc with the
radius the same as that of the large
cylinder
INTERSECTIONS OF CYLINDERS
• Large intersections can be plotted
accurately by selecting points along the
curve to project.
INTERSECTIONS OF CYLINDERS
• When the cylinders are the same diameter,
their intersections appear as straight lines
in the adjoining view
INTERSECTIONS AND TANGENCIES
Examples of a narrow prism
intersecting a cylinder
INTERSECTIONS AND TANGENCIES
Intersections of a keyseat and
cylinder and a small hole and
cylinder.
FILLETS AND ROUNDS
• A rounded interior corner is called a fillet.
A rounded exterior corner is called a round.
• Sharp corners are usually avoided in
designing parts to be cast or forged
because they are difficult to produce and
can weaken the part.
FILLETS ROUNDS AND RUNOUTS
Small curves called runouts are used to represent fillets that connect with plane
surfaces tangent to cylinders
FILLETS ROUNDS AND RUNOUTS
The runouts should have a radius equal to that of the fillet and a curvature of
about one eighth of a circle.
FILLETS AND ROUNDS
Runouts from different filleted intersections will appear different owing to the
shapes of the horizontal intersecting members.
FILLETS AND ROUNDS
CONVENTIONAL EDGES
• In some cases, the true projection may be misleading.
• There is a conventional way of showing rounded and filleted edges for the sake of
clarity.
CONVENTIONAL EDGES
• Added lines depicting rounded and filleted edges, give a clearer representation,
even though it is not the true projection.
• Project the added lines from the intersections of the surfaces as if the fillets and
rounds were not present.
NECESSARY VIEWS
One-View Drawing
NECESSARY VIEWS
Two-View Drawing
NECESSARY VIEWS
Three-View Drawing
NECESSARY VIEWS
When deciding which views to show, keep in mind the following:
• Show sufficient views to completely describe the shape.
• Show the right-hand view instead of the left-hand view if both show the
object equally well.
• Choose the top view rather than the bottom view.
• Show long parts horizontally on the sheet for two reasons: (1) they fit better;
(2) they tend to appear even longer when shown vertically.
• Make it your goal to communicate the information clearly. If an additional
view helps toward this goal, show it.
• Keep in mind that drawings are easier to read and update if they are simpler,
rather than more complex.
NECESSARY VIEWS
PARTIAL VIEWS
• A view may not need to be complete to
show what is necessary to clearly
describe the object.
• This is called a partial view and is used
to save sketching time and make the
drawing less confusing to read.
PARTIAL VIEWS
• If the view is symmetrical, you can
draw a half-view on one side of the
centerlinecor break out a partial
view,
• The half-views should be the near
side.
PARTIAL VIEWS
• Occasionally, the distinctive features of an object are on opposite sides.
• In cases like this, two side views are often the best solution.
• The views are partial views, and certain visible and hidden lines have been
omitted for clarity.
Conventional Breaks
• To shorten the view of a long object, you can use break lines.
• When the long handle of the rake is shown to scale, the details of the drawing are
small and hard to read
• Using a break to leave out a portion of the handle allows the scale for the ends to
be increased to show the details clearly.
Conventional Breaks
