Magnesium Alloy Fasteners: The Lightest Structural Metal in the Bill of Materials
At 1.8 g/cm³, magnesium alloys are the lightest structural metals in commercial use — 35% lighter than aluminum. In weight-critical housings, magnesium fasteners close the loop.
Where magnesium hardware makes sense
AZ91-family cast or machined fasteners serve camera and drone structures, portable equipment frames and interior automotive parts — joints where the parent metal is magnesium and the fastener must not become a galvanic spear. Matching fastener alloy to parent alloy eliminates the worst couple.
The galvanic reality
Magnesium is the most active structural metal: coupled with steel or aluminum in an electrolyte, it corrodes preferentially — and fast. Managing this defines magnesium engineering:
- Isolate dissimilar fasteners with coated steel (zinc-nickel), nylon washers or sealed joints.
- Prefer magnesium or compatible-aluminum fasteners for through-wall joints.
- Seal faying surfaces; keep electrolytes out and the couple stays theoretical.
Strength and cost position
AZ91 delivers ~230–260 MPa — between cast aluminum grades and 6061-T6 — at the lowest density. Topprecision supports magnesium-structure programs with compatible fastener sets, galvanic-compatibility test data, and coating recommendations validated in salt-spray joint testing.
