Fastener Materials & Manufacturing Flashcards

Which stainless steel grade is most susceptible to sensitization (carbide precipitation) when welded?

Answer: Type 304

Type 304 stainless steel is susceptible to sensitization because its carbon content can form chromium carbides at grain boundaries during welding.

What is the Rockwell hardness scale typically used to measure hardness of standard steel fasteners?

Answer: Rockwell C (HRC)

The Rockwell C scale (HRC) is the standard for measuring hardness of heat-treated steel fasteners, using a diamond indenter.

Silicon bronze fasteners are preferred in marine environments primarily because they offer:

Answer: Excellent corrosion resistance without galvanic issues with copper alloy fittings

Silicon bronze resists corrosion in marine environments and is galvanically compatible with copper alloy fittings, preventing galvanic corrosion.

Which cold heading operation forms the head of a bolt by upsetting the wire blank?

Answer: Upsetting

Upsetting compresses the end of a wire blank axially, causing the metal to flow radially outward to form the fastener head.

What minimum tensile strength (psi) is required for an SAE Grade 5 bolt?

Answer: 120,000 psi

SAE Grade 5 bolts have a minimum tensile strength of 120,000 psi for diameters up to 1 inch.

The term 'proof load' for a fastener refers to:

Answer: The maximum axial load the fastener must withstand without permanent deformation

Proof load is the specified load a fastener must sustain without any measurable permanent deformation, representing the elastic limit.

Which material property describes a fastener's ability to absorb energy before fracturing?

Answer: Toughness

Toughness is the ability of a material to absorb energy (area under the stress-strain curve) without fracturing, combining strength and ductility.