ENGR 2160 - Engineering Graphics
Chapter 12 (Bethune)
and other reference materials
HOW DOES EVERYTHING COME TOGETHER?
We’ve made our drawings.
Orthographic, Auxiliary, etc.
We’ve dimensioned out drawings
We’ve indicated tolerances in our drawings.
So what’s next ?
Let’s briefly understand various terms used in
Assembly, parts list, blocks ….
WORKING OR ASSEMBLY DRAWINGS
In this chapter we will talk about assembly drawings.
We will talk briefly about guidelines for titles,
revisions, tolerances and release blocks.
WORKING DRAWINGS OR CONSTRUCTION
are a set of
are given to
perform work or
Different type of assembly drawings include:
Design assemblies, or layouts
Working drawing assemblies
Outline or installation assemblies
Inseparable assemblies (weldments, etc.)
These drawings are sometimes called top drawings because
they are the first of a series of drawings used to define a group
of parts that are to be assembled together.
The group of drawings are referred to as a family of
drawings and may include subassemblies, modification
drawings, detail drawings and parts list.
Views should show how the parts fit together and suggest
function of the unit
A sectional view maybe used to show internal areas critical to
Hidden lines are typically not needed
Assembly drawings are usually not dimensioned
Detail drawings contain all of the necessary
information to manufacture a part
Detail drawings are also called:
Piece part drawings
Each part of the assembly is identified by an
assembly or item, number. These numbers are
enclosed in a circle or ellipse.
Use circled numbers called balloon numbers or
ball tags to identify parts in an assembly
Circles are placed in orderly horizontal or
vertical rows and not scattered over the sheet
AutoCAD includes many different drawing
templates that conform to ANSI and ISO
These templates automatically include:
A partial release block
DRAWING TEMPLATES – BORDER & BLOCK
File -> New -> Tutorial-iMfg
File -> New -> Tutorial-mMfg
Explode block first
DRAWING TEMPLATES – REVISION BLOCK
Drawings in industry are constantly being changed.
Products are improved or corrected, and drawings
must be changed to reflect and document these
Each drawing revised is listed by letter in the
revision block. The revision letter is also added to
the field of the drawing in the area where the
change was made.
DRAWING TEMPLATES – TOLERANCE BLOCK
Tolerance block is placed next to the title block
and lists the standard tolerances that apply to
the dimensions on the drawing.
DRAWING TEMPLATES – RELEASE BLOCK
A release block contains a list of approval signatures or initials
required before a drawing can be released for production.
The required signatures are:
DRAWING TEMPLATES – RELEASE BLOCK
Drawn – The person that created the drawing
Checked – Drawings are checked for errors and compliance with
company procedures and conventions. Some companies have
checking department others have a senior person or the drafting
Design- The engineer in charge of the design project. The designer
and the drafter maybe the same person
Stress/Wts – Department or the person responsible for the design.
Materials- person in the production department who checks the
design and makes sure that the necessary materials and machine
times for the design are available. This person may also schedule
Customer – The customer for the design may have a representative
on site at the production facility to check that its design requirement
A parts list or bill of materials (BOM) typically
Partidentification number (PIN)
Description of each part
Quantity required in the assembly
Abbreviationscan be used to indicate quantities that are
not known such as AR (as required) and EST (estimated
Open EX 9-1
Create Title Block, Release, Revision and
Tolerance Blocks. Refer to Figure 12-23 (page
Tolerance of part 1 has changed from +/-.05 to
A detail drawing is a drawing of a single part.
The drawing should include all the information necessary to
accurately manufacture the part including:
And any manufacturing requirements.
Detail drawings include the following in the same places they
are found in the assembly drawings.:
And Revision Blocks
These notes are used to provide manufacturing information
that is not visual, for example:
torque requirements for bolts
and shopping instructions.
These notes are usually located above the title block on the
right side of the drawing.
These notes are listed by number.
If the note applies to a specific part of the drawing, the note
number is enclosed in a triangle.
These numbers (enclosed in triangles) are also drawn next
to the corresponding areas of the drawing.
A Design Layout is not a drawing.
This is like a visual calculation sheet used to size and locate
parts of a design developed.
A design layout allows you to build the assembly on paper.
When drawings are created on a drawing board an initial layout
is made locating and sizing the parts. Then the individual detail
drawings and the assembly drawing are traced from the layout.
This is done in AutoCAD using the “Layer” command.
Read Sample Problem SP 12-1 (Page 496). DO
NOT DO THE DRAWINGS
End of Chapter - 12