Which property is most important for steel members that must withstand tensile loading in a bridge?

Which property is most important for steel members that must withstand tensile loading in a bridge?

• A. Hardness
• B. Tensile strength
• C. Electrical conductivity
• D. Magnetic permeability

Answer: (B)

When a steel bridge member is pulled in tension, the key concern is how much stress it can withstand before it breaks. That is what tensile strength measures—the maximum stress the material can endure in tension before fracture. A higher tensile strength allows the member to carry larger loads or be designed with smaller cross-sections while still remaining safe, which is essential for preventing sudden failures under pulling forces. Hardness relates to how resistant the surface is to denting or wear, not to how much load the material can hold in tension. Electrical conductivity and magnetic permeability concern how electrons or magnetic fields move through the material, not its strength under tensile loading. So the property that directly governs a steel member’s ability to resist tearing apart under pull is tensile strength.

When a steel bridge member is pulled in tension, the key concern is how much stress it can withstand before it breaks. That is what tensile strength measures—the maximum stress the material can endure in tension before fracture. A higher tensile strength allows the member to carry larger loads or be designed with smaller cross-sections while still remaining safe, which is essential for preventing sudden failures under pulling forces.

Hardness relates to how resistant the surface is to denting or wear, not to how much load the material can hold in tension. Electrical conductivity and magnetic permeability concern how electrons or magnetic fields move through the material, not its strength under tensile loading. So the property that directly governs a steel member’s ability to resist tearing apart under pull is tensile strength.