Practice Test Geeks(CFS) Certified Fastener Specialist Practice Test
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Corrosion Resistance & Coatings Flashcards

7 cards from real CFS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

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  1. Silicon bronze fasteners are most appropriate for use in which application?

    Answer: Marine wood boat construction

    Silicon bronze fasteners are widely used in marine wood boat construction because they resist seawater corrosion and are compatible with wood without causing staining.

  2. What is the primary disadvantage of using stainless steel fasteners in chloride-rich environments such as swimming pools?

    Answer: Stainless steel is susceptible to pitting and crevice corrosion from chlorides

    Chloride ions attack the passive chromium oxide layer on stainless steel, initiating pitting and crevice corrosion even in grades like 316.

  3. Phosphate coatings (Parkerizing) on fasteners are commonly used as a:

    Answer: Base layer to improve adhesion of oil or paint topcoats

    Phosphate coatings provide excellent adhesion for subsequent oil, wax, or paint topcoats rather than serving as a standalone corrosion barrier.

  4. Which grade of 316 stainless steel is preferred for welded fastener assemblies in corrosive environments to prevent sensitization?

    Answer: 316L

    316L has a lower carbon content (max 0.03%) that prevents chromium carbide precipitation at weld heat-affected zones, avoiding sensitization and intergranular corrosion.

  5. A fastener specified as 'zinc plated per ASTM B633, SC1' would have a minimum zinc thickness of:

    Answer: 0.0002 in (5 µm)

    ASTM B633 SC1 (Service Condition 1) specifies a minimum zinc thickness of 5 µm (0.0002 in) for mild indoor service conditions.

  6. What phenomenon causes hydrogen to diffuse into steel during acid pickling or electroplating, potentially causing fastener failure?

    Answer: Hydrogen embrittlement

    Hydrogen embrittlement occurs when atomic hydrogen diffuses into the steel lattice during acid pickling or plating, reducing ductility and causing delayed fracture under load.

  7. Fasteners made from Alloy 400 (Monel) are specified primarily when resistance is needed to:

    Answer: Hydrofluoric acid and seawater

    Monel 400 (nickel-copper alloy) provides outstanding resistance to hydrofluoric acid and excellent corrosion resistance in seawater and marine atmospheres.