A bit, socket or an adapter is also a tool. These items come in many designs and sizes and you need to select the right design and size for your application. Screwdriver bits are exposed to continuous strain during the fastening process. Depending on the fastening application, maximum wear resistance and highest elasticity are key items. Mountz offers assortment of high quality bits for all screw applications. Also, Mountz offers the ability to make custom bits.