Drilling into brick walls.

Sure you can, if the mortar is in good condition and you have proper anchors.

I was going to drill into a brick wall to hang an antique fire insurance plaque. I it better to drill the concrete or the brick?
My masonry drill is a good ole piece of work.

Usually you get a stronger hold in the brick itself. I have done it both ways, with good results, but I wasn't hanging an anvil up there any of the times.

Good, Ill probably set an anchor in a bit of a masonary epoxy. The fire plaques have two holes to hold them (usually in the eaves of a building)

I haven't done it in years and that was - I think - into the long hardened mortar; I think I remember using a concrete bit. Ah, I see, they're called masonry bits as well.

The mortar at the apartments I just retired from is washing out and in need of constant repair. Naturally I would go in the bricks there. Each situation must be weighed, according to your own judgment.

Definitely.

they make a chemical liquid "Hardener" for mprtar now, just like the hardener for rotten wood. It gets pulled through the spalling concrete via the increased permeability. Then I guess it sets up with a chemically stable gel like those silica gels that harden ito ROCKS over night.
Pretty nifty if you hve an old stone barn or outbuilding that is beginning to deteriorate. Then, on top, (I assume that the mortar is faced a bit), its filled in with new concrete with some of the same silca gel

That will be a project for the new guy. I retired from there a week ago.