CFS Fastener Materials & Manufacturing 3

Question 1

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

Accepted Answer

Type 304

Answer

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

Question 2

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

Accepted Answer

Rockwell C (HRC)

Answer

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

Question 3

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

Accepted Answer

Excellent corrosion resistance without galvanic issues with copper alloy fittings

Answer

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

Question 4

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

Accepted Answer

Upsetting

Answer

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

Question 5

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

Accepted Answer

120,000 psi

Answer

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

(CFS) Certified Fastener Specialist Practice Test