The ultimate tensile strength of structural mild steel is about A. 160 N/mm2 B. 260 N/mm2 C. 420 N/mm2 D. 520 N/mm2

The correct answer is C. 420 N/mm2.

The ultimate tensile strength (UTS) of a material is the maximum stress that a material can withstand before it fails. It is usually measured in megapascals (MPa) or newtons per square millimeter (N/mm2).

Structural mild steel is a type of steel that is used in construction and other applications where strength is important. It has an UTS of about 420 N/mm2.

Option A is incorrect because the UTS of structural mild steel is not 160 N/mm2.

Option B is incorrect because the

UTS of structural mild steel is not 260 N/mm2.

Option D is incorrect because the UTS of structural mild steel is not 520 N/mm2.