I purchased (1) 1.5", (1) 2" & (1) 2.5" all for coring through brick. Do not waste money on the pilot bit. It's actually easier without (at 12" long, it's not very stable and actually caused more problems in the first hole I did). My first hole was sloppy looking so I had to re-gropup. To rectify this, I purchased a couple of 1"x 6"x 6' pine boards and wood hole saw bits the same diameter as my masonry coring bits. I placed the 1x board vertically against the wall resting it on the ground, marked the center points, removed it and use the wood hole saw through the 1x creating a template. I Positioned the 1x board back on the wall, using my foot to put pressure on the bottom and used the wifie to hold the top (no need to anchor the 1x to the wall, you only need it for a few seconds to get the coring bit started - you only need about 1/8" into the brick & and you're done w/ the wood template). I was able to remove the 1x and relieve the wife and then continue my core. Worked awesome! Perfect cores. I've cored about (15) holes through the brick all perfect. I used a Hilti 16-C Hammer Drill (do not use the hammer drill option for core bits - just the rotary drill option). I have a medium hard red clay brick and it took me about 4-5 minutes per hole (after the templating). Do not use water - these are dry coring bits. Hope this helps. These are very reasonably priced masonry coring bits. I would buy their products again. RK.