Following are examples of three metamorphic rocks and a list of their uses. Marble is a metamorphic rock that is used to make floor tiles, counter tops and it is carved into statues and was used extensively in the building of the Roman Colosseum and other historic buildings. Slate is another metamâ¦.
A hex key, Allen key or Allen wrench is a tool of hexagonal cross-section used to drive bolts and screws that have a hexagonal socket in the head (internal-wrenching hexagon drive).
In a broader sense the term can be used synonymously with master key to refer to any key, keycard or other device capable of opening a variety of locks. In US English usage, 'skeleton key' is also occasionally used to mean a standard lever lock key. It is sometimes misapplied to refer to any antique key.