316 Introduction to Austenitic Stainless Steel 316

316 is a molybdenum-alloyed chromium-nickel austenitic stainless steel, engineered to deliver stronger corrosion resistance than 304 stainless steel.

Chromium (Cr): 16.0%–18.5% – Forms a dense passive oxide film to resist oxidation and general corrosion
Nickel (Ni): 10.0%–14.0% – Stabilizes austenitic microstructure, improves ductility and low-temperature impact toughness
Molybdenum (Mo): 2.0%–3.0% – Key element to resist chloride-induced pitting and crevice corrosion
Carbon (C): ≤0.08% – Minimizes the risk of intergranular corrosion
Balance: Iron, plus trace manganese and silicon

Core Material Properties

Outstanding Corrosion Resistance With molybdenum addition, 316 withstands salt mist, seawater, sweat, weak acids and chemical solutions far better than 304. It is the top choice for medical, marine, coastal and chemical exposure environments.
Non-magnetic Base Structure Fully non-magnetic after solution annealing; faint magnetism may occur after heavy cold working. Ideal for precision medical and electronic parts sensitive to magnetic interference.
Superior Ductility & Formability High plasticity supports bending, deep drawing and complex profiling. Its powder exhibits excellent fluidity for MIM manufacturing of micro thin-walled irregular components.
Excellent Low-temperature Performance No brittle transition at sub-zero temperatures, suitable for cryogenic fluid control and medical hardware.
Mechanical Characteristics Moderate tensile strength in annealed state. It cannot be hardened by quenching; slight hardness improvement is only achievable via cold forming. For high-load wear-resistant moving parts, 17-4PH martensitic stainless steel is recommended.
High-temperature Oxidation Resistance Continuous operating temperature up to 870°C, with stable anti-oxidation performance under repeated heating cycles.

Metal Injection Molding (MIM) 316 powder boasts good flowability and high sintered density post debinding and sintering. It is widely adopted for miniature medical instruments, wearable fluid connectors and marine precision fittings, with low cracking risk due to high inherent toughness.
Wide Compatibility with Surface Finishes Supports mirror polishing, sandblasting, passivation, PVD coating and AF anti-fingerprint film, meeting hygiene and aesthetic standards for medical devices and premium wearables.
Heat Treatment Limitations Not hardenable through quenching. Solution treatment relieves forming stress and restores full corrosion resistance; aging treatment cannot boost hardness.

Superior resistance to chloride corrosion compared to 304
Excellent biocompatibility, tolerates repeated high-temperature steam sterilization without rusting
Easy to polish for premium appearance, ideal for hygiene-critical decorative components
High toughness, resistant to fracture for frequently assembled tiny parts

Higher raw material cost than grade 304
Low hardness and poor wear resistance, not applicable for high-friction moving parts such as gears and hinges
Cannot be strengthened by heat treatment

Medical Devices: Surgical forceps, tweezers, minimally invasive instrument components, auxiliary implant parts
Marine & Fluid Equipment: Liquid cooling connectors, seawater pipeline fittings
High-end Smart Wearables: Watch bezels, skin-contact buckles for coastal wearers
Chemical & Food Processing: Anti-corrosion fluid valves, precision food machinery fittings
Consumer Electronics & Audio: Premium decorative parts exposed to sweat and salt