Hex 3mm

Is the hexagonal part for a hex drill bit, for a drill bit of 3mm.Is Ideal for low force.I made it just for cleaning 3mm holes. Put the bit in the hole, now against a piece of wood hamer it dow. It goes 8mm in. The hole is conic up to the half. It will be tight once is done.I printed mine out of PLA and worked well for my porpouse.