The way an impact driver works makes standard screwdriver bits almost useless. The forces involved require a specifically designed bit to withstand the large amount of torque. These Axcaliber bits can withstand the punishment from an impact driver. The manufacture of them is of a very high standard. The tip and hex shank need to be hard to prevent excessive wear. The central portion must be elastic enough to absorb the shock of the impact action without snapping. A correctly formed tip for a close fit in the screw head minimises the possibility of cam-out and damage to the surrounding area. 25mm overall length with Pozi drive (PZ2) tips.