Bosses are often
added to parts to as mounting points and stand offs. In the die
cast knob example shown here the added boss will become the mounting
point for the knob to be pressed onto a shaft. It is critical to
maintain uniform wall thickness in a boss feature and to do this a
hole is almost always added to the middle of the boss. In addition,
draft is required on the outer and inner surfaces of the boss.
Bosses may be difficult to fill, as it is hard for molten metal to
flow up a tall narrow boss feature. Adding generous fillets as well as ribs will
help metal flow into the boss. “Fillets” have already been covered and “Ribs” will be
covered next.
