However, during tempering, elements like chromium, vanadium, and molybdenum precipitate with the carbon. If the steel contains fairly low concentrations of these elements, the softening of the steel can be retarded until much higher temperatures are reached, when compared to those needed for tempering carbon steel. This allows the steel to maintain its hardness in high temperature or high friction applications. However, this also requires very high temperatures during tempering, to achieve a reduction in hardness. If the steel contains large amounts of these elements, tempering may produce an increase in hardness until a specific temperature is reached, at which point the hardness will begin to decrease. For instance, molybdenum steels will typically reach their highest hardness around whereas vanadium steels will harden fully when tempered to around . When very large amounts of solutes are added, alloy steels may behave like precipitation hardening alloys, which do not soften at all during tempering.