1. Overview

Selecting the correct alloy for exterior and marine-grade fasteners is critical to preventing galvanic corrosion and stress cracking. While both Austenitic grades offer excellent strength, their chloride resistance differs significantly due to molybdenum content.

2. Technical Specifications & Composition

Specification / PropertyGrade 304 (A2)Grade 316 (A4)
Chromium (Cr)18.0 – 20.0%16.0 – 18.0%
Nickel (Ni)8.0 – 10.5%10.0 – 14.0%
Molybdenum (Mo)—2.0 – 3.0%
PREN Value (Pitting Resistance)~18 – 20~23 – 25
Tensile Strength (MPa)500 – 700500 – 700
Yield Strength (0.2%, MPa)≥ 210≥ 210

3. Engineering Recommendations

  • Grade 304 (A2-70): Suitable for standard industrial machinery, indoor structural assembly, and urban architectural applications located more than 15 km from the coastline.
  • Grade 316 (A4-70 / A4-80): Mandatory for marine vessels, chemical processing equipment, offshore wind structures, and any installation exposed to direct salt spray or road de-icing salts.

4. Compliance & Standards

All Ferrovic stainless steel fasteners comply with ISO 3506-1 and ASTM F593 testing requirements. Material Test Reports (MTR 3.1) are available upon batch delivery.

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Older Ferrovic Corporation (M) SDN BHD: Specialized Lubricants ISO 9001:2015