304 / 316 / 2205 Stainless Steel Fastener Selection & Performance Comparison

304 / 316 / 2205 Stainless Steel Fastener Selection Guide and Performance Comparison

Stainless steel fasteners are widely used in photovoltaic projects, outdoor engineering, marine facilities and chemical equipment due to excellent rust resistance and mechanical stability. 304, 316 and 2205 are the most common grades, but their corrosion resistance, strength and applicable working conditions vary greatly. Improper material selection is the main cause of rusting, loosening and fracture in engineering projects. This guide sorts out their core differences and professional selection standards for seawater, chemical and PV outdoor environments.

1. 304 Stainless Steel: Economical & Universal for General Scenarios

304 stainless steel features good toughness and basic anti-rust performance with cost advantages. It is suitable for indoor equipment, dry outdoor environments and ordinary mechanical assembly. It can withstand normal atmospheric conditions and meet the needs of civil and general industrial equipment.

It is not suitable for coastal salt fog, acid-base environments and long-term humid conditions, which will cause pitting corrosion and thread failure.

2. 316 Stainless Steel: Enhanced Salt Spray Resistance for Coastal & Outdoor Projects

With molybdenum element added, 316 stainless steel greatly improves resistance to chloride corrosion. It is the mainstream choice for coastal photovoltaic brackets, seaside facilities and outdoor steel structures. It performs well in humid, rainy and sea breeze environments with stable anti-rust ability and excellent fatigue resistance.

As a medium-grade anti-corrosion material, 316 cannot adapt to strong acid and extreme seawater immersion scenarios.

3. 2205 Duplex Stainless Steel: High Strength & Super Corrosion Resistance for Harsh Conditions

2205 duplex stainless steel has double-phase structure with higher strength, about 1.8 times that of ordinary stainless steel. It excels in pitting resistance, crevice corrosion resistance and stress corrosion resistance. It can adapt to seawater immersion, heavy salt fog, chemical acid-base and high-temperature humid environments, widely used in marine engineering, chemical equipment and high-end new energy projects.

4. Professional Selection Rules

304 for indoor and dry general assembly; 316 for common outdoor and coastal projects; 2205 for marine, chemical and extreme harsh working conditions.

5. Professional Supporting Service from zhjiali

zhjiali stocks complete specifications of 304, 316 and 2205 fasteners and provides non-standard customization, material testing and salt spray test reports. We offer targeted material selection solutions for different industries to avoid hidden dangers such as corrosion and loosening.