History of anthracite coal mining in Pennsylvania History of anthracite coal mining in Pennsylvania There are two types of coal found in Pennsylvania: anthracite (the “hard coal” found in Northeastern Pennsylvania below the Allegheny Ridge southwest to Harrisburg; also called “stone coal”, “rock coal” in the 1800s) and bituminous (“soft coal”, found west of the Allegheny Front escarpment). Anthracite coal is a natural mineral with a high carbon and energy content that gives off light and heat (produced energy) when burned, making it useful as a fuel. It was possibly first used in Pennsylvania as a fuel in 1769, but its real history begins with a documented
Carbon steel Carbon steel Carbon steel is a steel with carbon content up to 2.1% by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels. As the carbon percentage content rises, steel has the ability to become harder and stronger through heat treating; however, it becomes less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.