A washer used to obtain a 'finished' look. Usually used with oval head screws. Split Lock. The most common style of washer used to prevent nuts and bolts from backing out. External Tooth Lock. A washer with external 'teeth' Used to prevent nuts and bolts from backing out. Internal Tooth Lock. A washer with internal 'teeth' Used to prevent nuts and bolts from backing out.
(March 2009). A metropolitan area network (MAN) is a computer network larger than a local area network, covering an area of a few city blocks to the area of an entire city, possibly also including the surrounding areas.istributed-queue dual-bus (DQDB) refers to the metropolitan area network standard for data communication specified in the IEEE 802.6 standard. With DQDB, networks can extend up to 20 miles (30 km) long and operate at speeds of 34â155 Mbit/s.
Metropolitan Area Definition and Delineations. OMB establishes and maintains the delineations of Metropolitan Statistical Areas, Metropolitan Divisions, and Micropolitan Statistical Areas solely for statistical purposes.