Search specific heat capacity values for metals and engineering alloys by grade, designation or material family. Compare heat capacity in J/kg·K and kJ/kg·K.
Specific heat capacity describes how much thermal energy is required to raise the temperature of a given mass of material by a specified amount. It is commonly represented by c and its SI unit is joules per kilogram-kelvin (J/kg·K).
A material with a higher specific heat requires more energy to produce the same temperature increase in the same mass. A material with a lower specific heat requires less energy for the same temperature change.
Specific heat is different from thermal conductivity. Thermal conductivity describes how readily heat travels through a material, whereas specific heat describes how much energy the material stores for a given temperature increase.
The heat required to change the temperature of a material can be estimated from the relationship between mass, specific heat and temperature change.
This is a basic sensible-heat calculation. It does not include phase changes, heat losses, temperature-dependent specific heat, radiation, convection or other process effects.
| Material | Specific Heat | J/kg·K | Relative Heat Capacity |
|---|---|---|---|
| Aluminum | ~0.897 kJ/kg·K | 897 | High for a common engineering metal |
| Copper | ~0.385 kJ/kg·K | 385 | Low to moderate |
| Iron | ~0.449 kJ/kg·K | 449 | Moderate |
| Carbon Steel | ~0.49 kJ/kg·K | 490 | Moderate |
| 304 Stainless Steel | ~0.500 kJ/kg·K | 500 | Moderate |
| 316 Stainless Steel | ~0.500 kJ/kg·K | 500 | Moderate |
| Titanium | ~0.523 kJ/kg·K | 523 | Moderate |
| Nickel | ~0.444 kJ/kg·K | 444 | Moderate |
| Silver | ~0.235 kJ/kg·K | 235 | Low |
| Gold | ~0.129 kJ/kg·K | 129 | Very low |
These two properties are often confused because both are involved in thermal engineering, but they describe different physical behaviors.
| Property | Unit | What It Describes | Example |
|---|---|---|---|
| Specific heat capacity | J/kg·K | Energy required to change the temperature of a unit mass. | Aluminum stores relatively large amounts of heat per kilogram for a given temperature increase. |
| Thermal conductivity | W/m·K | How readily heat conducts through a material. | Copper transfers heat very efficiently. |
| Thermal diffusivity | m²/s | How quickly a temperature disturbance spreads through a material. | Depends on conductivity, density and specific heat. |
| Factor | Effect | Engineering Importance |
|---|---|---|
| Temperature | Specific heat can change with temperature. | High-temperature thermal calculations should use temperature-dependent data. |
| Alloy composition | Different alloying elements can alter heat capacity. | Do not automatically use the pure base-metal value for an alloy. |
| Phase | Solid and liquid phases can have different heat capacities. | Phase changes require additional thermal-energy calculations. |
| Heat treatment | Microstructure can affect thermal properties. | Important when precise material-property data is required. |
| Composition variation | Commercial grades have specification ranges. | Reference values should not replace certified material data for critical designs. |
Specific heat is important in heating and cooling calculations for furnaces, heat-treatment equipment, casting operations, machining, welding, thermal processing, heat exchangers and energy-storage systems.
For a simple sensible-heating calculation, the required thermal energy increases with mass, specific heat and temperature change. This makes specific heat particularly useful when estimating the energy required to heat a batch of metal from one temperature to another.
For example, a large aluminum component may require substantial energy to heat because aluminum has relatively high specific heat. Copper has a lower specific heat per kilogram, but its much higher thermal conductivity means it can transfer heat rapidly through the component.
Real industrial heating processes are more complicated. Furnace efficiency, heat losses, radiation, convection, contact conditions, changing material properties and heating rate can all affect actual energy consumption.
What is specific heat capacity? Specific heat capacity is the amount of thermal energy required to raise the temperature of one kilogram of a material by one kelvin. Its SI unit is J/kg·K.
What is the specific heat of aluminum? Pure aluminum has a specific heat of approximately 897 J/kg·K near room temperature. Aluminum alloy values vary by grade and temperature.
What is the specific heat of copper? Copper has a specific heat of approximately 385 J/kg·K near room temperature.
What is the specific heat of steel? Common carbon steels typically have specific heat values around 450–500 J/kg·K near room temperature, although the exact value depends on grade and temperature.
What is the specific heat of stainless steel? Common stainless steels such as 304 and 316 are typically around 500 J/kg·K near room temperature.
Does a high specific heat mean a metal conducts heat well? No. Specific heat and thermal conductivity are different properties. A metal can have high specific heat while having relatively low thermal conductivity.
Does specific heat change with temperature? Yes. Specific heat generally varies with temperature, and the variation can become important over large temperature ranges.
Why is specific heat important when heating metal? It helps determine how much energy is required to raise the temperature of a known mass by a specified amount.
Does specific heat matter during welding? Yes. Specific heat influences how much energy is needed to change the temperature of the material and therefore contributes to thermal behavior during welding and other heating processes.
Can these values be used for precise engineering calculations? They are suitable as general reference values. For critical calculations, use temperature-specific data from the applicable material standard, manufacturer or verified engineering database.