Extrusion Dies For Aluminum Heat Sinks

An extrusion die is a hardened steel disk with a shaped opening. Hot aluminum is forced through it under huge pressure, emerging as a continuous profile. For heat sinks, the die opening includes narrow slots that form the fins. We arrange the slots to distribute the metal evenly, preventing the fins from bending or breaking as they exit.

The die steel is heat-treated to withstand high temperatures and wear. A special surface treatment on the bearing area helps the aluminum glide through with less friction. This leads to a smooth surface finish on the heat sink, which improves thermal contact later when mounting electronic components.

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After each extrusion run, the die needs to be cleaned of aluminum residue and inspected for cracks. With proper care, it can produce kilometers of profile. Many aluminum extrusion plants order these dies repeatedly because consistent fin shapes are key to the cooling performance of the final product.