HOLES AND POCKETS
Holes and pockets may be produced either by incorporation into the
pattern (provided size limitations, draft requirements and direction of draw
are satisfactory), or by insertion of separately
made cores. These cores will give a flexibility of design to the casting,
but generally at a higher production cost.
The limiting factors in casting holes and pockets are depth (L), degree of
draft (d) and the narrowest dimension across the hole (a).
Because of the diverse nature of cored holes, it is best
to consult your foundry on aspect ratios and core capabilities. Remarkable
complexity can be achieved.