Phillips Head Screw Bits The most common type of fastener has got to be the #2 Phillips head bit, but we've even seen adaptation here. The name “Phillips” comes from its inventor Henry F. Phillips in the 1930s. These types of screwdrivers have a pointed cross-head tip that matches a self-centering, cross-head screw. 3. What is the best brand of screwdriver bits? Hex head bits or Allen bits have 6 flat sides and the screws or bolts that go with them are very common. You're probably already familiar with these thanks to the hex keys—AKA Allen wrenches—that come with your Ikea furniture. The bits are exactly the same, they just fit in a screwdriver or drill instead. 2. What are the most commonly used screwdriver bits?