In plate-girder terminology, the distance between the outer faces of the two flanges is called the ______ of the girder.

Introduction / Context:
Correct geometric definitions in plate girders are essential for analysis and detailing. Terminology such as overall depth, clear depth, and effective depth are frequently examined in steel design problems.

Given Data / Assumptions:

• Two flange plates (or flanges) separated by a web plate.
• We want the term for the full distance from the outside face of the top flange to the outside face of the bottom flange.

Concept / Approach:
Overall depth is defined as the full, outside-to-outside distance between the flanges. Clear or effective depth may exclude cover plates, fillets, or refer to centroidal lever arm used in simplified bending calculations, but the standard term for outside-to-outside is overall depth.

Step-by-Step Solution:

Verification / Alternative check:
Check detailing drawings: overall depth is the dimension used for fabrication clearances and envelope sizing; effective depth is more a design-derived measure linked to the neutral axis location.

Why Other Options Are Wrong:
Clear depth or effective depth exclude certain components or are used in different contexts; “design” or “net” depth are not standard terms for outside-to-outside geometry.

Common Pitfalls:
Mixing effective lever arm (distance between resultants) with geometric overall depth; ignoring cover plates that increase the outside dimension.

Final Answer:
overall depth