A nut with a built in washer like flange. Tee. A nut designed to be driven into wood to create a threaded hole. Square. A four sided nut. Prevailing torque lock. A non-reversible lock nut used for high temperature applications. K-Lock or Kep. A nut with an attached free-spinning external tooth lockwasher.
adjective. The definition of metropolitan is a city or something related to a city. A city and the immediate locations surrounding it is an example of a metropolitan area.
2. (Human Geography) constituting a city and its suburbs: the metropolitan area. 4. (Government, Politics & Diplomacy) of or belonging to the home territories of a country, as opposed to overseas territories: metropolitan France.