Straight scoop on scandium

Guns Magazine, August, 2007 by Edwin J. Westerman

As a professional metallurgist who's developed strong aluminum alloys for 40 years, I'd like to clarify the term "scandium" as applied to certain strong, light, gun frames. Such "scandium" frames are not made from this expensive rare earth element with mediocre mechanical properties. Rather, the frames are made from strong aluminum alloys whose major strengthening elements include zinc, magnesium and copper, which may total more than 10 percent of the alloy.

Scandium is added only in small amount, perhaps about 0.2 percent, to prevent recrystallization of the aluminum alloy during high-temperature heat treatment, commonly applied at 850 degrees F or higher. Scandium allows the alloy to retain the fibrous, worked structure resulted from prior metal working processes, such as forging or extruding. This structure is stronger than a recrystallized structure and, perhaps more importantly, better resists the stress-corrosion cracking tendency inherent in certain strong aluminum alloys.

Scandium is a good thing ... just know it's only a very tiny additive to an aluminum-framed gun.

Edwin J. Westerman

San Ramon. Calif.