CD Drafter Materials & Manufacturing Processes Flashcards

Which material property describes a metal's ability to be drawn into a wire without breaking?

Answer: Ductility

Ductility is the property that allows a material to be drawn into a wire or stretched without fracturing.

On a technical drawing, a surface finish symbol with a value of 125 µin Ra indicates:

Answer: A relatively smooth machined surface

125 µin Ra is a standard machined surface finish commonly used for general-purpose machined parts.

Which manufacturing process uses a rotating cutting tool to remove material from a stationary workpiece?

Answer: Milling

Milling uses a rotating multi-tooth cutter to remove material while the workpiece is fed into it.

What does the abbreviation 'HR' indicate when specified next to a material designation on a drawing?

Answer: Hot Rolled

HR stands for Hot Rolled, indicating the steel was processed above its recrystallization temperature.

A casting process that forces molten metal into a reusable steel mold under high pressure is called:

Answer: Die casting

Die casting injects molten metal into permanent steel dies under high pressure, producing dimensionally accurate parts.

Which heat treatment process hardens only the outer surface of a steel part while keeping the core tough?

Answer: Case hardening

Case hardening (carburizing or nitriding) adds carbon or nitrogen to the surface layer, creating a hard exterior with a tough core.