It is not strengthened by heat treatment, instead becoming stronger due to strain hardening, or cold mechanical working of the material.
The alloy composition of 5059 is:[1] The mechanical properties of 5059 vary significantly with hardening and temperature.
Its high strength and good corrosion resistance make it an excellent match for yachting.
[citation needed] Arc welding reduces mechanical properties to no worse than –O hardening condition.
The relatively low decrease in ultimate strength is extremely good performance for an aluminium alloy.