Ultra-high carbon steel contains between 1 and 2 percent carbon.

Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12–2.0%.
Ultra-high carbon steel contains between 1 and 2 percent carbon.
Medium Carbon Steel contains between 0.25 -0.7% carbon and used for machine components requiring high strength and good fatigue resistance.
High-carbon steels are decidedly more difficult to weld than low- or medium-carbon steels. However, a variety of measures are available to ensure a strong weld.
Carbon steel is steel in which the main interstitial alloying constituent is carbon in the range of 0.12–2.0%.
The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values.
In carbon steel grades the last two digits indicate the nominal carbon content.
Silicon-Manganese Steel, resulfurized and rephosphorized Carbon Steels