¼ inch hex drive impact drivers do not use a chuck system, which means that the bits for the drill fit directly into the machine. These bits are shaped in a hex pattern and simply clip into the drill. These drill drivers are commonly used for screwing and socket work, and can accept hex screw bits and socket bits. These drills can also be used for drilling, however hex shaped drill bits are required to fit in these drill drivers. Standard round drill bits will not fit.

• The key consideration when choosing a drill driver is the maximum drilling diameter required. Drill drivers with 1/4' hex drives; the drill bit fits straight into the machine rather than tightened into a chuck. This drill can only be fitted with 1/4' hex shank.

• **Battery words** Most professional drill drivers have a variable speed function and a variety of torque settings. Additionally there is often a choice between single, 2 or 3 speed gears; a low speed and higher torque setting is used for screw driving whilst a higher speed is used for drilling metal or wood for example. Combi drills and impact drivers have higher torque settings.