Review on HighFree BI Metal Mandrels Drywall Plastic by James Nedumaran

This is the cheapest 6 inch bi metal bit and it works great! The signature 6-inch bimetal bits are over $43, but it's less than half that amount, and they come in two other sizes! It seems very difficult. I used a 6 inch saw to cut holes in the kitchen cabinet, drywall, masonite siding and sheathing (4 holes total) and it held its edge. It was for installing a hood.