…everything wears out over time. Fortunately, replacing the first two is much easier. This is a set of 13 drill bits from 1/16" to 1/4" increasing in 1/64" increments. No case is supplied, but everything fits into a sleeve that encloses the hex shank and is designed for provides a more secure fit in the drill. They may be "titanium coated" but for $15 they are not for professional use.. but for the ranks of home suckers, which I'm proud to belong to. You can 2- Lasted 3 years so I throw away the old ones that lasted too long Good value for money and timely supply from Vine 5 stars.