Aluminum is a light weight and strong non-ferrous metal, it is, 

this feature brings it to the first option for outdoor use.

Outdoor threads are antibacterial, do not smell and do not protect your health. Since it is resistant to ultraviolet rays, it can be used easily in sunny weather.

Teak is a hardwood species with a high oil rate.It is ideal for outdoor furniture, and is resistant to all climatic conditions.