The Berlin Gau Badge 1926-1936

[der-hase-fee]

Because they are not signs of cast, but the result of long use.

A variety of irregularities can affect metal castings. The most common defect is porosity. Porosity refers to the voids—the empty spaces—on or within what should be a solid metal casting.



Source: https://imprexusa.com/metal-casting-defects/