6061 Aluminum Alloy

DENSITY: 2.70 g/cm³
YIELD STRENGTH: 276 MPa
HARDNESS: 95 HB

Precipitation-hardened aluminum alloy containing magnesium and silicon.

Introduced by Alcoa in 1935 as Alloy 61S, it is strengthened by magnesium-silicide precipitates formed during artificial aging.
The common T6 temper is produced by solution treating near 530 °C, quenching, then aging at about 160-180 °C for several hours.
Excellent extrudability and weldability make it the default alloy for bicycle frames, structural extrusions, and marine hardware.