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).
A car key or an automobile key is a key used to open and/or start an automobile. Modern key designs are usually symmetrical, and some use grooves on both sides, rather than a cut edge, to actuate the lock.