Malleability Comparison of Common Engineering Metals Among the following materials, which exhibits the greatest malleability (ability to be hammered/rolled into thin sheets without cracking)?

Introduction / Context:
Malleability is a metal’s ability to withstand compressive forming into thin sheets without cracking. It is distinct from ductility (ability to draw into wire). Ranking common metals by malleability helps in selecting materials for sheet forming, deep drawing, and coinage applications.

Given Data / Assumptions:

• Room-temperature behavior is considered.
• Materials listed are commercially pure or typical engineering grades.
• Forming is predominantly compressive (rolling/hammering to sheet).

Concept / Approach:
Gold and silver are the most malleable metals overall, but they are not options here. Among the given choices, copper is exceptionally malleable, forming very thin sheets with excellent surface finish. Lead, while very soft, tends to tear under severe working and lacks the workability and strength balance of copper. Wrought iron and soft steel are formable but not as malleable as copper; they typically require more controlled processing to reach equivalent thinness without defects.

Step-by-Step Solution:
Define malleability as sheet-forming capability without cracking.Compare typical behavior: copper sheets and foils are readily produced at room temperature.Lead is soft but not superior in producing strong, very thin, crack-free sheet.Soft steel and wrought iron are workable but fall below copper in malleability.

Verification / Alternative check:
Industrial practice: copper foils for electronics and roofing illustrate its high malleability; similar ultra-thin products from steel or wrought iron are more challenging.

Why Other Options Are Wrong:
Lead: very soft yet prone to tearing; not the best at extreme sheet thinning.Soft steel / wrought iron: formable with strength but not as malleable as copper for very thin sheet work.

Common Pitfalls:
Equating softness with malleability; copper combines softness with high-quality sheet formability better than lead.

Final Answer:
Copper