"Bob La Londe" fired this volley in
:

They are clean. ** after degreasing, ** I have inspected them. They
are right on the edge of fitting up, but I just do not want to hit it
that hard to seat them up. With a rubber mallet it works fine, but
sometimes loosens up on a hard bump in certain types of work.

I've never had problems with an "inertial fit".

I clean everything, make sure there are no burrs or non-monotonic
portions of the tapers. Then I install the taper into the chuck by hand
fit and hand pressure, them hand-propel the assembly from about 18" up
tang end down on a block of aluminum or heavy Type-I PVC (never on steel,
please!).

It seldom works loose before the taper comes loose from the socket in the
drill press, even when running self-feeding bits. It's kind of like the
action you'd use to seat an axe bit or maul on a handle (which cost me an
exploded finger tip one year! OUCH!)

LLoyd