Chapter 2 Introduction
 Why would a
product designer choose a die
casting over a component manufactured by
another competing process?
 What are the capabilities of a product made
with a die casting?
2-1
Chapter 2 Objectives
 List the advantages of
using die castings
 Identify die casting applications
 List the characteristics of the optimum die
casting configuration
 Identify the components of the die casting
shot
2-2
New Terms
 Die
casting “shot”
 EMI
 Overflows
 Runner
 Sprue
2-3
Die Casting Advantage
 Produces components
at high speed
 Uses a range of durable metal alloys
 Faithfully captures the most intricate design
details
 So,
it’s the choice for:
• High volume
production components
• Lower-volume
production as well
2-4
Die Casting Applications
Agricultural machinery
 Automotive vehicles
 Building hardware
 Electrical and
electronic equipment
 Hand tools
 Home appliances
 Industrial products

Instrumentation
 Lawn and garden
equipment
 Office furniture
 Office machines
 Portable power tools
 Recreational
equipment

2-5
Optimum Configuration
 Fill completely with metal
 Solidify quickly without defects
 Eject readily from
the die
2-6
Principle 1
 Wall thickness should be
as consistent as
possible
•
•
•
•
•
No hard and fast rules
Wall section possesses a dense fine-grained skin
Defects likely in material in between walls
Wall sections should be as uniform as possible.
Thinner walls contribute a lesser heat load than
heavier walls and will have a longer die life
2-7
Principle 2
 Intersections of
walls, ribs and gussets
should blend with transitions and generous
radii
• Generous radii and transitions promote metal
flow and
internal integrity
• Radii and fillets enhance structural integrity
• Fillets reduce heat concentration in both the die
and castings
2-8
Principle 3
 Specify standard draft
• Draft is highly desirable on surfaces parallel to
the direction of die draw
• Recommended draft is determined by:
– The alloy
– The length of the dimension parallel to the die draw
– If the dimension is an inside or outside wall
2-9
Principles 4 and 5
 Eliminate or
minimize sharp corners
• Accommodate them at parting lines and at the
junctions of die components
• Break them with radii or chamfers
 Avoid undercuts
• May require machining operations or additional
die components, such as retractable core slides
2-10
Principle 6
 Dimensions with critical tolerances should
relate to only one die member
• Precision is greatest when related features are in
same piece of cavity steel
• Precision is reduced for relationships across the
parting line or to moving components
• Judicious use of ribbing can aid die filling and
strengthen the component
2-11
The Shot
 The result of
injecting metal into the die,
i.e., making a shot (verb), is also called
a shot (noun)
 Shot elements:
•
•
•
•
Runner
Biscuit
Overflows (not pictured)
Casting
2-12
Overflow
 A reservoir
for the first metal to flow through
the cavity
 Vents inside provide a path for air to get out
of the die
• A strategically placed overflow can be used to
add heat in a cold area of the die
 May
help eject the casting from the die
2-13
Summary
 Many
reasons to choose die casting over a
competing process
 Many product lines made from die castings
 6 principles must be followed to ensure
optimum design
2-14