What's the injustice, why are there bits for self-tapping screws and not enough for bolts? We will correct this mistake. That's why you will find bits that can be used to unscrew nuts and bolts from 6 to 19 mm. Accordingly, the set contains 16 bits for each size. The bits are made of durable and quality steel and have a standard shank of 1\4 inches. The length of each bit is 65mm. These bits are suitable for any screwdriver, drill or electric screwdriver and are always useful at home, in the car or garage.