John F. Kennedy was the US president during the Cuban Missile crisis General Secretary of the USSR was Nikita Krushchev and Fidel Castro was the Cuban ruler involved in this â¦ crisis.
What is the metal used for most electrical wiring and water pipes? Copper is the most common metal used in electrical wires because it has a structure which includes freely-moving negatively-charged particles-called electrons-which are es â¦ sential for the conduction of electricity.
Backing Rings. When joining two pipes, ensuring that they are properly aligned, held together, and to prevent leaks, a small piece of material called a backing ring is necessary. Backing rings can be either round, or square and are made typically from rubber or a metal such as chrome, carbon steel, or aluminum.