Warm is normal. The screws on a 600W dimmer go right into the heat
sink of the dimmer, so warm screws would be normal. And if the dimmer
is running too warm, just wait a while and the triac will short out and
you will have only an on-off switch with NO dimming.
The next step up from the 600W in-box dimmers is a dimmer with higher
wattage ratings, but the 1000W dimmers have external heat sinks. If you
can manage with the 600W dimmer (for how many years?) with it not going
bad, just stick with it.
It should be noted that the higher wattage dimmers will dissapate the
same power, but with their better heat sinking, their temperature will
be some lower. But they are not as pretty, since the heat sinking is
external. --Phil

Blake Patterson wrote:

It is a 600W max Lutron dimmer. This one, of the three I mention
having in the house, has by far the greatest load on it. There is
another one where the screws are slightly warm and it has 180W total
on it. This one has between 400 and 500W on it. It is also in a
PLASTIC phone-style box in the wall, not metal, oddly. Bad
construction, clearly. So the box itself is not helping as a
heatsink. The screws are quite hot (not too hot too touch, really,
after more experimenting), but the plastic faceplate on the dimmer
switch just feels warm.

Can't decide if this is a problemed switch or if I should leave it as
normal.

bp
--
Phil Munro Dept of Electrical & Computer Engin
Youngstown State University
Youngstown, Ohio 44555