Stainless Steel rods provide better corrosion resistance than HDG or zinc plated coated rods due in part to their alloy composition. There are different grades of stainless steel available for varying applications. There are also different sub-classes within the grades
that are relative to the alloy percentages in the composition.
A key element in corrosion protection is the percentage of Nickel in the fastener's composition. The standard "18-8" stainless, this grade is the most widely used and versatile stainless steel. It offers slightly better strength, but lower corrosion resistance to saltwater (sodium chloride).