Exam Questions And Correct Answers

CA C51 Structural Steel Contractor Exam Questions And Correct Answers (Verified Answers) Plus Rationale2026 Q&A| Instant Download Pdf

• What is the primary purpose of structural steel in construction?
• Decoration
• Support loads and provide structural integrity
• Fireproofing
• Thermal insulation

Rationale: Structural steel is used mainly for its high strength-to-

weight ratio to support loads and ensure structural stability.

• Which ASTM standard covers structural steel shapes?

A. ASTM A36

B. ASTM A500

C. ASTM A992

D. ASTM A53

Rationale: ASTM A992 specifies the material properties for structural

steel shapes used in building construction.

• What is the most common connection method for structural steel

beams?

• Glue
• Bolting and welding
• Screwing
• Nailing

Rationale: Bolts and welds provide strong, reliable connections in

structural steel assemblies.

• Which type of steel is commonly used for columns and beams?
• Stainless steel 1 / 3

• Tool steel
• Carbon steel
• Cast iron

Rationale: Carbon steel is preferred for structural members due to its

strength, ductility, and cost-effectiveness.

• What is the minimum fireproofing requirement for structural steel in a

high-rise building?

• None
• 5 minutes
• As specified by building code (e.g., 2-hour rating)
• 30 minutes

Rationale: Building codes require steel to have a fire-resistance rating

depending on building type and height.

• Which of the following is a common steel beam designation?
• W12x50
• W14x90
• L8x8
• S8x18

Rationale: W14x90 indicates a wide-flange steel beam 14 inches deep

and weighing 90 lbs per foot.

• What is the primary advantage of using structural steel over concrete?
• Lower cost
• Higher strength-to-weight ratio and faster erection
• No maintenance required
• Better fire resistance

Rationale: Steel provides higher strength per unit weight and allows

faster construction.

• What is the allowable stress of ASTM A36 steel in tension?
• 20 ksi
• 25 ksi
• 36 ksi
• 50 ksi

Rationale: ASTM A36 steel has a minimum yield strength of 36 ksi.

• Which welding process is most common in structural steel fabrication?
• Oxy-acetylene
• Shielded Metal Arc Welding (SMAW)
• Electron beam 2 / 3

• Laser welding

Rationale: SMAW is widely used in structural steel due to versatility

and reliability.

• What is the purpose of gusset plates in steel structures?
• Decorative finish
• Reduce vibration
• Transfer loads between beams and columns
• Increase corrosion resistance

Rationale: Gusset plates connect members at joints and distribute

loads efficiently.

• Which corrosion protection is commonly applied to steel in

outdoor environments?

• Painting
• Galvanization
• Oil coating
• Waxing

Rationale: Galvanization provides a zinc coating that protects steel

from rust.

• What is the typical bolt size used for A325 structural bolts?
• 1/4"
• 1/2" to 1"
• 2"
• 3/8"

Rationale: A325 bolts commonly range from 1/2" to 1" diameter in

structural connections.

• Which factor affects the buckling of a steel column?
• Column length
• Slenderness ratio
• Color of paint
• Type of foundation only

Rationale: Slenderness ratio determines the tendency of a column to

buckle under axial load.

• What is the typical depth-to-span ratio for a steel beam?

A. 1:5

B. 1:10

C. 1:15

D. 1:25

• / 3