Hog-outs vs. Castings
Are hog-outs, or castings, best for your application?
Here are some factors to help you decide:
Hog-outs are often chosen when parts are close-tolerance, or have complex shapes.
They are advantageous because typically the material is zero-porosity, and more
metallurgically uniform. As a result of this, there are lower, (and sometimes no) X-ray
certification requirements. Hog-outs also allow for a wider range of alloy choices.
Hog-outs can be machined from an alloy that is not castable.
Engineering costs for hog-outs are generally lower, because no casting tooling is
required – that is, no patterns, molds or dies. And the initial operation requires
just a simple fixture rather than a fixture that accounts for all the normal variations
and delicacy of a casting.
The machining of hog-outs also avoids the of residual stresses and porosity that may
occur during the casting process. Finally, hog-outs are able to hold far tighter tolerances,
thus, material thickness can often be reduced, along with total component weight –
a huge advantage for aerospace and automotive and other applications.
Hog-outs are also advantageous for low-volume programs.
Cast parts require less machining to make a finished part. Because cast parts are
near-net, only detail machining, rather than complete machining, is needed.
Using less material sometimes offsets the greater labor burden of the casting.
Casting also has an advantage in that you can form hollow passages using sand cores.