Below is a list of Magnesium Alloys manufacturers from Downingtown, Pennsylvania. Magnesium alloys are formed from a base of elemental magnesium and another metallic element. A type of alkaline earth metal, elemental magnesium is a strong, yet light-weight metal that is also highly flammable and burns with a particularly bright light. As a comparable metal to aluminum, magnesium is the third most commonly used type of structural metal.