Description of HHIP 5000 0032 Center Countersink Diameter
Body diameter is 1/4". Drill diameter is 7/64". Made of ground high speed steel. Ground from solid. 60 degree countersink angle fits all standard centers.
I bought 2 pieces for a project and tried to use both. They were so blunt they couldn't even drill through the copper. After sharpening they worked fine but I don't have a good sharpening setup so I couldn't get them perfect. It really annoys me that something brand new can't cut something as soft as brass.