🔍 Key Concepts

• Properties of copper compared with steel when heated and cooled • What annealing means in metalworking (softening vs. hardening) • Effect of rapid cooling (quenching) vs. slow cooling on copper

💭 Think About

• Ask yourself: when we anneal a metal, do we want it to become softer and more workable, or harder and more brittle? • Think about how copper behaves differently from steel when you heat it to a dull/cherry red and then cool it quickly in water or oil. • Which option describes a process commonly used to relieve stress and increase ductility (bendability) of copper pipe?

✅ Before You Answer

• Be clear on the definition of annealing (what is the goal of the process?). • Identify which choices involve quenching and what quenching usually does to metals. • Check which option matches standard plumbing/pipefitting practice for softening copper pipe for bending.