Introduction
Detailed Explanation of Thermal Properties of Metal Materials
General Introduction to Fire Resistance
First, metals are inherently non-combustible and do not fall under the same flammability ratings as plastics, such as UL 94. Under normal atmospheric conditions, all metals offer top-tier fire resistance, neither burning nor producing toxic fumes.
Stainless Steel (SUS304, SUS316)
Stainless steel boasts outstanding high-temperature resistance, with a continuous operating temperature range of 425°C to 500°C. Its melting point is extremely high, ranging from approximately 1375°C to 1450°C. However, stainless steel has a relatively low thermal conductivity of approximately 16 W/m·K, meaning it conducts heat slowly and dissipates heat poorly. Therefore, special attention must be paid to heat accumulation during processing.
Aluminum Alloy (AL6061, AL6063)
Aluminum alloys have a continuous temperature resistance of approximately 120°C to 150°C. Their melting point is much lower than that of steel, ranging from approximately 580°C to 650°C. One of aluminum alloys’ most notable properties is their excellent thermal conductivity, which can reach as high as 167 to 205 W/m·K. This ability to quickly conduct heat away makes them ideal for applications such as heat sinks and electronic enclosures.
Magnesium Alloy (AZ91D, AZ31B)
Magnesium alloys have a continuous temperature resistance of approximately 120°C, the lowest of the three metal types. They also have a relatively low melting point, ranging from approximately 490°C to 610°C. Magnesium alloys exhibit excellent thermal conductivity, ranging from 72 to 116 W/m·K, dissipating heat better than stainless steel, making them suitable for lightweight parts requiring heat dissipation.
Conclusion
From high-temperature-resistant stainless steel, highly conductive aluminum alloys, to ultra-lightweight magnesium alloys, each metal’s thermal properties determine its most suitable application. Understanding these differences will help you make the most precise material selection for your project.

