Chapter 5 Overview
 Casting die
is the other major component
 Casting die has four functions:
• Hold molten metal in shape of desired casting
• Provide means for molten metal to get into the
space where it is held in desired shape
• Remove heat from molten metal to solidify it
• Provide for removal of the solidified metal
5-1
Chapter 5 Objectives
 Identify the
four types of casting dies
 Identify the three major casting die modules
 Identify the purpose of each major die
component
5-2
New Terms

Cavity
• The void or empty space in the die that fills with metal to make
the casting

Gate
• The smallest restriction in the alloy flow path, located at the
edge of the casting

OEM
• Acronym for Original Equipment Manufacturer

Overflows/lifters
• Small pockets of alloy located around the edge of the casting
5-3
New Terms cont.

Runner
• Die cast alloy distribution system within the casting die

Shot
• All the injected material

Vacuum vent
• Helps get the air out of the die cavity.

Vent
• Path from the die cavity to outside the die
5-4
Die Ownership
 The OEM owns the
tooling required to make
the die casting
• If GM opted to purchase casting from a custom
producer, the custom producer would buy
casting die from a toolmaker and then sell the die
to GM
• If GM opted to manufacturer the casting in its
own plant, GM would buy the die from a
toolmaker directly
5-5
Types of Dies

Single cavity die
• Produces one
casting at a time

Multiple cavity die
• Produces more than
one casting at a time

Family die
• Produces a number of different parts

Unit die
• OEM owns the unit die and the custom die caster owns the
mold base or unit die holder
5-6
Unit Die System

Advantages
• Lower tooling costs
• Shorter lead times
• Potentially lower
piece part costs

Disadvantages
• Reduced flexibility in part design
• Limited size
• Possible problem moving tooling from one vendor to
another without additional tooling costs
5-7
Mold base
Steel envelope that is designed to hold all the other
die components together
 Usually made from a pre-hardened steel such as a
P-20 or AISI 4140

5-8
Stationary half mold base
 Acts
as container for stationary die cavities
 Provides means for attaching stationary die
half to machine
 Couples injection system to the die
 Provides a means for aligning to two die
halves
 Has several components
5-9
Stationary Half Mold
Base Components
 Clamp slots
 Guide pins
 Pryslots
 Mounting/clamp plate
5-10
Moving half mold base
 Acts
as container for the die cavities
 Couples ejection system to the cavities
 Provides means for aligning the two die
halves
 Components include:
• Guide bushings
5-11
Ejector box
 Provides a
means for mounting moving half
mold base to moving machine platen
 Supports moving half mold base against
machine closing force and force of injection
 Couples machine ejector system to die
ejector system
 Has several components
5-12
Ejector Box Components
 Parallels/rails
 Clamp plate
 Support pillars
5-13
Ejector system
Inside the ejector box
 Provides one of four critical die functions, to
‘provide for removal of the solidified metal’
 Has several components

5-14
Ejector System Components
 Ejector pins
 Return
pins
 Ejector plate
 Ejector return plate
 Guided ejection
5-15
Die Cavity
 Cavity
blocks
 Core pins
 Slides
Casting
 Carrier
 Wedgelock
 Cam pin
 Cooling lines
 Heaters
Core pin
5-16
Die Cavity cont.
 Several
cavity features share same
terminology as the die cast shot
•
•
•
•
•
Sprue
Runner
Gate
Overflows
Vents
5-17
Miscellaneous Components
 Biscuit block
 Sprue bushing
 Sprue post
 Stop buttons
 Quick eject cam
and pins
5-18
Summary
 Casting die
is the other major component
• Has four functions
 Castings can
be manufactured by the OEM or
purchased from a custom producer
 4 casting die forms: single cavity, multiple
cavity, family and unit
 A typical die contains 3 modules: stationary
mold base, moving mold base and ejector box
5-19
Summary cont.
 Unit dies are
not complete dies; have certain
advantages and disadvantages for the OEM
 There are many components to casting dies
•
•
•
•
•
•
Mold base
Stationary half mold base
Moving half mold base
Ejector box
Ejector system
Die cavities
5-20