There are two main types of die casting: hot-chamber and cold-chamber. In hot-chamber die casting, molten metal is kept inside the die casting machine, while in cold-chamber die casting the molten metal is poured into the machine from outside. Both processes use pressure to force molten metal into a die cavity to create parts. Cold-chamber die casting is more economical for large production quantities, provides good accuracy and surface finish, and requires less floor space than hot-chamber die casting.

1. Cold-Chamber
Die Casting &
Hot-Chamber
Die Casting

2. Die casting
 Die casting is a process in which
molten metal is forced by pressure
into a metal mold known as a ‘die’.
There are two methods employed:
(1) Hot chamber die casting
(2) Cold chamber die casting

3.  Hot chamber die casting
 Materials to be cast is molten
inside the machine.
 Used for materials having low
melting temperature , i.e. zinc, tin,
and lead.

4.  Cycle in hot chamber casting
(1)with die closed and plunger withdrawn,
molten metal flows into the chamber.
(2) plunger forces metal in chamber to flow
into die, maintaining pressure during
cooling and solidification.

6.  Cold chamber Die casting
 Materials to be cast is molten
outside the machine.
 Used for materials having low
melting temperature , i.e. zinc, tin,
and lead.

7.  Cold Chamber Die Casting

8.  Cycle in cold chamber
casting
(1) with die closed and ram withdrawn,
molten metal is poured into the chamber.
(2) ram forces metal to flow into die,
maintaining pressure during cooling and
solidification.

9. Cold-Chamber Die Casting

10. Advantages and
Disadvantages
 Advantages :
◦ Economical for large production quantities.
◦ Good accuracy and surface finish .
◦ Thin sections are possible .
◦ Longer die life is obtained.
◦ Less floor space is required.
 Disadvantages:
◦ Only economical for nonferrous alloys.
◦ Heavy casting can not be cast.
◦ Cost of die and die casting equipment is
high.
◦ Not economical for small run.