Classification of rolled steel beam sections as per Indian Standards According to Indian Standards practice, rolled steel beam sections are grouped into how many series?

Introduction / Context:
Rolled steel beam sections in India have historically been categorized into standard series (for example, ISMB, ISJB, ISLB, ISWB in older practice). Recognizing the count of series helps engineers navigate steel tables and select appropriate sections during preliminary design.

Given Data / Assumptions:

• Conventional/classical IS practice regarding rolled beam series.
• Question tests recognition of the standard grouping rather than exact nomenclature updates.

Concept / Approach:
The Indian Standards historically provided four principal series of hot-rolled beams differing by depth-to-weight characteristics: medium, junior, light, and wide flange (beam). Though modern editions have updated designations, the examination concept references the classic four series.

Step-by-Step Solution:

Verification / Alternative check:
Cross-check old steel tables used academically: they present four beam series under Indian Standards, affirming the conventional answer.

Why Other Options Are Wrong:
Two or three understate the variety; five or six exceed the classical categorization and cause confusion with other rolled shapes (channels, angles).

Common Pitfalls:
Mixing current proprietary/market designations with classical IS series counts; confusing beams with channels or universal columns.

Final Answer:
Four series