What can I use instead of a hex key?
What can I use instead of a hex key? 2. Screwdrivers. Sometimes you can use small types of flathead screwdrivers as a hex wrench by putting the end in the socket so that the two edges of the screwdriver work as leverage in the hole to turn it. The wider the socket on the bolt or nut, the wider the flathead screwdriver you will want to use. How do I know my hex key size? Hex keys are measured across-flats (AF), which is the distance between two opposite (parallel) sides of the hexagon....Sizing0.7, 0.9, 1.0, 1.25, 1.3, 1.5.2 to 6...