Approximate carbon content range in steel: which of the following best represents the typical carbon percentage in steels (excluding cast irons)? (Choose the standard range used in materials engineering.)

Introduction / Context:
Steels are iron–carbon alloys with carbon content lower than cast irons but higher than wrought iron. Knowing the approximate carbon range helps classify steels (low, medium, high carbon) and guides selection for forming, welding, and strength requirements.

Given Data / Assumptions:

• Cast irons typically contain about 2%–4.5% carbon.
• Wrought iron contains very low carbon (near zero).
• Steels occupy the intermediate carbon range.

Concept / Approach:
Standard references place steel carbon content roughly between 0.05% and 1.75%, with sub-ranges used in design: low carbon (≈0.05%–0.30%), medium (≈0.30%–0.60%), and high carbon (≈0.60%–1.0%+), and some specialty tool steels extending toward the upper end. This excludes cast irons at higher carbon levels.

Step-by-Step Solution:

Verification / Alternative check:
Metallurgy texts and standards align with the 0.05%–1.7%+ range depending on classification; practical limits vary slightly by specification but fit this band.

Why Other Options Are Wrong:

• 1.50%–5.6%: includes cast irons and exceeds typical steel ranges.
• Exactly 0.25%: represents only one low-carbon steel point.
• None of these: incorrect because the correct range is listed.

Common Pitfalls:
Confusing tool steels or special alloys with cast iron; assuming a single value characterizes all steels.

Final Answer:
0.05% to 1.75%