Low Carbon Steel - Low carbon steel is a fairly soft and relatively weak material. It does, however, have good ductility and toughness as well as being easily machinable, weldable. It is also inexpensive to produce. Low carbon steel contains less than 0.25% carbon. It cannot be strengthened by heat treating. Strengthening can only be accomplished by cold working.The yield strength of low carbon material is about 40,000 psi and tensile strength is in the 60,000 to 80,000 psi range.
SAE J429 Grade 1, ASTM A307 Grade A and SAE J429 Grade 2 all fall into the low carbon category.