the star head screws come in different sizes and so they have different headinsert sizes also. It is incredible the way they have revolutionized building today. With he onslaught of cordless and fuel cell systems it is a heck of a lot easier to build with screws of this type. A really great aspect is that if you put up a wall and don't like it, or find some measurement off, you can go back to those star head screws and back them all out. In doing lay out work they are invaluable that way. They very very seldom don't fit, hardly ever strip out and will take about all the punishment imaginable.