A screw gun only drives screws and is used for installing materials like drywall or plywood whose surfaces or edges must be exactly level. It can drill holes but only to a certain extent. Meanwhile, a drill mainly bores holes but can also function as a screw gun provided that an aftermarket part called a dimpler is attached to its chuck. The bits of screw guns can spin at a higher speed than drills (up to 6,000 rpm compared to 3,000 rpm), but the latter can supply more torque.