
P.O.
Box 406
821 South Downing Street
Piqua, Ohio 45356
Phone: 1-800-752-9509
1-937-773-4134
Fax: 1-937-773-3694
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| Strength
of the Past |
| Versatility
of the Present |
| Shape
of the Future |
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| Understanding
Castings |
| Aluminum, Bronze & Zinc |
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| Making the Pattern |
To make
quality castings, a foundry must have quality
patterns. A basic pattern, called a
"loose pattern," can be used for a very
small quantity of production pieces, however the
quality may suffer. Mounting the "loose
pattern" on a board to fit a certain flask
makes the job easier and can improve the quality
somewhat, but, again, it is only for short runs
in production. Wood or epoxy patterns are used
for medium production. These patterns are mounted
on a "Follow Board," which is a board
made to follow the contours of the pattern. For
long runs and top quality, the pattern is made
into an aluminum matchplate, usually with half
the pattern on each side of the matchplate. These
patterns maintain their durability and withstand
the usage that the large production runs give
them. |
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| An Inside Look at the
Mold |
The picture at
the right illustrates a small
"Squeezer" type mold with the pattern
removed. This mold is ready to be poured with
metal.
To make this mold, the top
(Cope) half of the flask is removed from the
bottom (Drag) half. The matchplate (with half of
the pattern on each side) is inserted between the
Cope and Drag. The flask is then placed on the
"Squeezer" with the Drag half in the
upward position. The Drag is filled with sand,
then rammed and jolted until the sand is settled.
A board is placed over the top of the Drag and
the mold is completely rolled over so the Cope
half is facing upward. The Cope half is filled
with sand, then rammed and squeezed. Once the
pouring hole, or "Sprue," is cut into
the sand, the Cope is lifted off the Drag and the
pattern is removed, leaving the mold ready for
pouring. |
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| The
Metal...properties and applications |
The
casting of pure aluminum isn't feasible as it
presents many problems in the foundry. Other
elements are therefore added to improve
properties and castability. The elements most
alloyed with aluminum are copper, silican,
magnesium, and to a lesser extent, manganese,
iron, zinc, and nickle. The effect of the added
elements is to increase fluidity, machinability,
strength, and hardness. Our most popular alloy,
#319 aluminum, is an all-purpose metal. We filter
and degas this metal until we get
"aircraft" quality. We have Almag 35,
A-356.2, 355, 356, and #713 and ZA12 zinc. In
copper alloys, we have 85-5-5-5, 81-3-7-9,
80-10-10, and 415-9-C Aluminum Bronze. |
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| Pouring
the Metal |
The
melting, the degassing, and the POURING of
the metal have a great deal to do with quality
castings. Our employee's take great care with all
metals, and we take vacuum tests constantly
throughout each work day to test for gas in the
melt. When gas is found, corrections are made
immediately. Many intricate castings take special
care in pouring, as some must be poured very
hard, while others a gentle, smooth flow of metal
through the mold produces the best casting. These
things are only garnered through experience, and
being here since 1920 has provided us with the
needed expertise.
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| The
Finishing Process |
In
obtaining the right finish for any casting, one
should first consider the ascast smoothness of
the casting, then the mechanical finish, and
finally the finish to be applied to the surface
of the casting. Most aluminum castings from the
foundry have a good finish without further
treatment, however we do have in-house wire
brushing, tumble blast machines, plus many
chipping and grinding tools. Out of house
treatment (alodining, painting, etc.) can be
provided, along with complete machining of the
product. For fan props, we can also furnish
complete balancing along with machining, boring,
set screw, etc., so props can be placed on a
motor shaft without any problems. |
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