A numerical value in weight percent, calculated from a mathematical equation, designed to relate the combined hardening effect of various alloying elements used in making carbon steel to an equivalent amount of carbon. Be reducing the carbon content in the steel and adding controlled amounts of various elements the desired strength levels can be achieved by proper heat treatment. In addition, the steel will have good weldability and low temperature notch toughness. The Carbon Equivalent (CE) formula is: CE = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15 Depending on customer and industry specifications, CE can be required as low as 0.40% maximum and as high as 0.50% maximum

A metric measure used to compare the emissions of the different greenhouse gases based upon their global warming potential (GWP). Greenhouse gas emissions in the U.S. are most commonly expressed as "million metric tons of carbon equivalents" (MMTCE). Global warming potentials are used to convert greenhouse gases to carbon dioxide equivalents. Carbon dioxide equivalents can then be converted to carbon equivalents by multiplying the carbon dioxide equivalents by 12/44 (the ratio of the molecular weight of carbon to carbon dioxide). Thus, the formula to derive carbon equivalents is: MMTCE = (million metric tons of a gas) * (GWP of the gas) * (12/44) (EPA)