This is an FTG review Maximum Torque - 5 adjustable countersinks #4, 6, 8, 10, 12, value set with hex key - conical drill bits fixed with pin. I bought these last week because I needed to countersink screws for the bookshelves I'm building. So far I've only used a 7/32" drill bit. It's worked fine so far, but then again I've only drilled the holes so far. My project requires drilling 120 holes. I don't know how well this exercise will work. / last. The bits seem brittle to me, but as I said, I only drilled 8 holes. I will update my rating (additional stars or reduction of star(s)) once I complete my project.