We get really really good results with the "Gold painted" Lenox carbide tipped holesaws. They're awesome, and last forever, haven't tried the "rem-grit" style, but another idea, is GreenLee has a specific hole saw just for this stuff. Check out they're website, and see what they offer in that line of things. My personal preference in the Lenox Gold, Carbide tipped hole saw. We use the 3 5/8ths for 3/0 cut ins. Take care and hope it helps! Brian
