Cast Iron – Typical Engineering Uses Among the following, which application is the most appropriate and common use of cast iron in civil/mechanical services?

Introduction:
Cast iron is an iron–carbon alloy with high carbon and silicon content. The question evaluates practical knowledge of where cast iron is preferred versus where steel or other materials perform better.

Given Data / Assumptions:

• Material: gray or ductile cast iron products.
• We compare uses across pipes, beams, columns, and tension members.
• We assume typical modern practice and safety considerations.

Concept / Approach:

Cast iron offers good compressive strength, damping, machinability, and corrosion resistance (with proper lining). It is brittle in tension and shows low ductility, which constrains structural use in bending/tension.

Step-by-Step Solution:

Verification / Alternative check:

Field catalogs list cast iron/ductile iron pipes with pressure ratings, coatings (cement mortar lining), and standard joints—reinforcing this choice.

Why Other Options Are Wrong:

Beams need ductility and toughness; columns and long struts risk brittle failure; tension members are unsuitable; reinforcement must bond and yield—cast iron is inappropriate.

Common Pitfalls:

Assuming compressive strength alone makes cast iron good for columns; overlooking brittleness and notch sensitivity.

Final Answer:

Small to medium diameter water pipes and drainage pipes