An impact driver has a collet that accepts 1/4-inch hex shank driver bits—to insert or release a bit you pull the collet forward. An impact driver is specifically designed to drive screws and bolts that would otherwise stall out a cordless drill. It does this by using concussive force to drive a screw into wood.Click to see full answer. Subsequently, one may also ask, what can you use an impact driver for?Impact drivers are high-torque tools primarily used for driving screws and tightening nuts (an operation known as nut setting). Their chuck accepts only bits with a ¼-inch hex shank.Subsequently, question is, can you use impact driver on car? The short answer is yes, but it depends. You can remove lug nuts of your car using an impact driver provided the nuts are tightened at the right amount of torque (80 to 100lb-ft) and your impact driver’s output torque is higher than 100lb-ft. In this regard, what size impact do I need? Impact wrenches that are ½ inch in size are a standard tool found in auto shops. This size wrench is the correct size for auto repairs, such as suspension and tire jobs. For construction sites, the ½ inch impact wrench is the perfect size for small to medium assemblies and disassemblies.What size impact driver do I need for lug nuts?I recommend staying near the middle in terms of size. So, go for either a 3/8-inch impact wrench or even better, a 1/2-inch impact wrench. These are the best sizes because they offer enough power to get even very tough lug nuts out, but at the same time, they won’t apply too much torque.