I was hanging some shelves on my kitchen walls. It's an interior wall of a 100 year old addition, these seem to be drywall glued directly to red brick, maybe plaster with dry wall glued to it. I didn't trust plastic anchors because of the weight and the unknown stability of the drywall, so I used Tapcon screws to reach through the half inch of drywall and get into the brick.
Seemed easy, but I had a serious problem with masonry bits. I was using a 7.5A Skil hammerdrill and only 5/32 holes, but the carbide tips broke off in 3 of 9 holes. First was a well used Dewalt bit with hammer turned on, then a brand new Mastercraft bit which i used slower without hammer (didn't last 1 hole), and then I was down to no-name wobbly bits included for free with various tools over the years. I don't think they did any worse, I had to treat them like gold (slower drilling, no hammering, pausing, blowing on the bit it to cool it), still broke one, but these cheap things got me through the job.
Anyone know why carbide bits would fail like this? Never had this happen before, but I don't do a lot of this. The biggest pain is that after it breaks, now you've got a hole with a carbide lost under a half inch of brick inside it... how can you even get it out?