Left.2021-25. Right.2021-25. Rotor screw. A Screw used to secure the Accessory Vacuum Pump to its mounting surface. A threaded stud that secures a vehicle's wheels to the wheel hub. Axle Hub Mounting Bolt. Brake Drum Screw. Disc Brake Rotor Bolt. Disc Brake Rotor Set Screw. Steering Knuckle Bolt. Included with: Hub & bearing, Knuckle assembly.