CFS Fastener Materials & Manufacturing 2

Question 1

Which heat treatment process increases the surface hardness of a steel fastener while maintaining a tough core?

Accepted Answer

Case hardening

Answer

Case hardening (carburizing or nitriding) hardens only the outer layer, leaving the core ductile and tough.

Question 2

What is the primary alloying element in 18-8 stainless steel fasteners?

Accepted Answer

Chromium and nickel

Answer

18-8 stainless steel contains approximately 18% chromium and 8% nickel, providing corrosion resistance.

Question 3

Which fastener manufacturing process involves forcing wire through a die to reduce its diameter?

Accepted Answer

Drawing

Answer

Drawing pulls wire through a die to reduce cross-sectional area and produce the correct diameter for fastener blanks.

Question 4

A Grade 8 hex bolt is made from which type of steel?

Accepted Answer

Medium-carbon alloy steel, quenched and tempered

Answer

SAE Grade 8 bolts are made from medium-carbon alloy steel that is quenched and tempered to achieve high strength.

Question 5

What manufacturing defect occurs when the grain flow in a fastener head is not continuous with the shank?

Accepted Answer

Cold shut

Answer

A cold shut occurs when two metal streams meet without fully fusing during forming, creating a discontinuity in the grain flow.

(CFS) Certified Fastener Specialist Practice Test