Search common steel grades and find indicative austenitizing temperature ranges, Fahrenheit conversions, typical quenching methods and practical heat-treatment notes.
Commonly referenced grades are listed below. Values are indicative reference ranges rather than universal production recipes.
| Grade | Equivalent / Standard | Category | Austenitizing Range | Typical Quench |
|---|---|---|---|---|
| Search for a grade above to populate the reference table. | ||||
The hardening temperature is the temperature to which steel is heated to establish the required austenitic structure before quenching. This is commonly called the austenitizing temperature.
The correct temperature depends strongly on the steel grade. Heating below the required range can result in incomplete transformation and inadequate hardness. Excessive temperature can promote grain growth, oxidation, decarburization and other undesirable effects.
Carbon steels, alloy steels, bearing steels, spring steels and tool steels can have substantially different transformation behavior. The presence of chromium, nickel, molybdenum, vanadium and other alloying elements can change hardenability and the required heat-treatment procedure.
This is why a temperature suitable for one steel grade should not automatically be applied to another grade, even when the two materials have similar carbon contents.
Medium-carbon steels such as 1045 are commonly austenitized at temperatures around the upper hundreds of degrees Celsius and then quenched. Alloy steels such as 4140 can use similar temperature ranges but often have substantially greater hardenability.
The appropriate quench medium and process depend on section thickness, geometry, required hardness and the exact material specification.
Tool steels can require considerably higher austenitizing temperatures than ordinary carbon steels. A2, D2, H13 and M2, for example, have different heat-treatment requirements.
Tool-steel manufacturers normally provide detailed heating, preheating, austenitizing, soaking and cooling procedures. Those instructions should take priority over generic reference values.
Hardening and tempering are separate stages. The hardening temperature is the high-temperature austenitizing stage performed before quenching. Tempering is performed afterward at a substantially lower temperature to modify hardness, toughness and residual stresses.
The temperatures in this tool are intended for preliminary reference and comparison. They should not be treated as a universal production heat-treatment specification.
What is the hardening temperature of 1045 steel?
A commonly referenced range is approximately 820–870°C, depending on the exact material and treatment procedure.
What is the hardening temperature of 4140 steel?
A commonly referenced range is approximately 830–870°C, with the final procedure depending on the applicable material specification and component.
What is the hardening temperature of 52100?
A commonly referenced austenitizing range is approximately 815–845°C, although bearing-steel processing requires careful control.
What is the hardening temperature of D2?
D2 is a high-alloy tool steel and is generally austenitized at a much higher temperature than ordinary carbon steels. Exact values should come from the tool-steel manufacturer's datasheet.
Can one hardening temperature be used for every steel?
No. Austenitizing temperature is grade-specific.
Does thicker steel automatically need a higher hardening temperature?
Not necessarily. Thickness mainly affects heating and soaking requirements. The specified temperature range remains dependent on the steel grade.
Is the highest temperature in the reference range always best?
No. The correct point within a specified range depends on the steel, section, furnace, desired properties and process.