I will not discuss the cutting edge or durability of these drill bits because they are simply "high speed steel". Nevertheless, the positive properties are obvious: FOR: 1. Beautiful high-quality metal drill index (housing).2. Very short "short" length. Just what you need for tight spaces.3. Black Oxide. CONS:* (None) Everyone should have a set of "short" baits. If these bits were about $10 more expensive in cobalt this little 1/16" - 1/4" set would be amazing. In this case the set would easily deserve 5 stars instead of 4.