A YouTube project video recommended a twist drill to cut a groove in the sides of a box to make a lid. I thought it was expensive but figured it might do. Now I see I could probably use one of my straight attachments and get similar results. There is nothing wrong with this beat, it goes through the popular software I use with ease. Since it is a bent part and I cut the grooves, the edge is rather rough. I would use a downward spiral, but I didn't want the tree to "walk" over me because of the upward bias. I found that I could get a smoother cut with this cutter simply by reducing the feed rate (instead of RPM). The bat is sharp enough that I don't feel the burn. The quality of the bit seems great for the price, I've just started using it so can't comment on durability. But the edges are polished and sharp. The bit rotates correctly and the top of the cutter makes a nice flat surface at the bottom of the slot. And yes, as my video shows, it's carbide.
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