Carbon Steel Seamless Pipes is a steel alloy consisting of iron and carbon. Several other elements are allowed in carbon steel, with low maximum percentages. They are manganese, with a 1.65% maximum, silicon, with a 0.60% maximum, and copper, with a 0.60% maximum. Other elements may be present in the steel in quantities too small to affect its properties. There are four types of carbon steel based on the amount of carbon in the alloy. Lower carbon steels are softer and more easily formed and steels with a higher carbon content are harder and stronger, but less ductile and harder to machine and weld.