316 stainless round bar (ASTM A276; GB 06Cr17Ni12Mo2) is engineered for extreme corrosion resistance, particularly in chloride-rich environments, with a specialized chemistry:
16.0–18.0% chromium (Cr): Forms a protective oxide layer to resist general corrosion.
10.0–14.0% nickel (Ni): Stabilizes the austenitic structure for ductility and low-temperature toughness.
2.0–3.0% molybdenum (Mo): Enhances resistance to pitting and crevice corrosion in saltwater-this is the key differentiator from 304.
≤0.08% carbon (C), ≤1.00% Si, ≤2.00% Mn, ≤0.045% P, ≤0.030% S: Trace elements that support machinability without harming corrosion resistance.
The molybdenum content makes 316 50–70% more resistant to chloride attack than 304, making it ideal for marine hardware, offshore platforms, and coastal architecture. It is 20–30% more expensive than 304 but justified for harsh environments. Made-in-China listings market it as "316 Marine-Grade Stainless Round Bar-Saltwater Resistant."