hex-shank bits

standards

Most bits fall into three categories:

1. The hex shank diameter is ¼" or 6.35 mm.   (normal-sized bits)
2. The hex shank diameter is 4 mm.   (micro screwdriver bits)
3. A Leatherman-style flat bit, which are designed to fit into any ¼" socket, since Leatherman bits are just truncated hex-shank bits.