100+ Free AZ ROC C-45 Sheet Metal Practice Questions

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Key Facts: AZ ROC C-45 Sheet Metal Exam

30 Questions

Official Question Count

PSI Candidate Information Bulletin

75 Minutes

Time Limit

PSI Candidate Information Bulletin

70%

Passing Score

Arizona Registrar of Contractors

$66

Exam Fee

PSI Services LLC

Open Book Computerized MCQ

Exam Format

PSI / AZ ROC Guidelines

100 Questions

Practice Question Bank

OpenExamPrep Practice Bank

The Arizona ROC C-45 Sheet Metal Examination consists of 30 scored multiple-choice questions administered in a 75-minute open-book PSI computer-delivered session with a 70% passing threshold ($66 exam fee). This online practice bank provides 100 realistic English-language practice questions with comprehensive technical explanations adapted for exam preparation.

Sample AZ ROC C-45 Sheet Metal Practice Questions

Try these sample questions to test your AZ ROC C-45 Sheet Metal exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1According to SMACNA HVAC Duct Construction Standards, what is the minimum sheet metal thickness (gauge) required for a 36-inch wide rectangular galvanized steel duct operating at a positive static pressure of 2.0 inches water gauge (in. w.g.) without intermediate transverse reinforcement?

A.24 gauge (0.028 inches)

B.26 gauge (0.022 inches)

C.22 gauge (0.034 inches)

D.20 gauge (0.040 inches)

Explanation: Per SMACNA HVAC Duct Construction Standards (Metal and Flexible, Table 1-4), a 36-inch wide unreinforced rectangular galvanized steel duct constructed for a 2 in. w.g. positive static pressure class requires a minimum metal thickness of 24 gauge (nominal 0.028 inch). Using thinner 26 gauge material would result in excessive wall deflection, oil-canning, or structural failure under operating static pressure.

2In rectangular sheet metal duct fabrication, which type of transverse joint connection consists of a flat strip with folded edges slipped over the turned-up flanges of adjacent duct sections on top and bottom, combined with drive cleats on the sides?

A.Companion angle flange joint

B.Flat S-cleat joint

C.Standing S-cleat joint

D.Pocket lock joint

Explanation: A flat S-cleat joint (often referred to as an S-and-drive connection) utilizes a flat S-shaped slip cleat on the top and bottom duct sides (longer dimensions) and drive cleats on the vertical sides. This is the standard transverse joint for low-pressure rectangular ductwork.

3What is the maximum allowable horizontal spacing for hangers supporting 24-gauge rectangular sheet metal ductwork installed in commercial HVAC systems per SMACNA and the International Mechanical Code (IMC)?

A.6 feet

B.8 feet

C.10 feet

D.12 feet

Explanation: Per SMACNA Duct Hanger Standards and IMC Section 603.10, horizontal rectangular sheet metal ducts must be supported at intervals not exceeding 10 feet. Hangers must be sized based on duct weight and cross-sectional area to prevent sag and joint stress.

4A technician is replacing a 24-inch wide by 12-inch deep rectangular duct with an equivalent round duct. Using the standard equivalent-diameter formula De = 1.30 x (a x b)^0.625 / (a + b)^0.25, what is the approximate equivalent round duct diameter?

A.14 inches

B.16 inches

C.18 inches

D.19 inches

Explanation: Substituting a = 24 and b = 12: (24 x 12)^0.625 = 288^0.625 = 34.4, and (24 + 12)^0.25 = 36^0.25 = 2.449. De = 1.30 x 34.4 / 2.449 = 18.3 inches. Round duct is stocked in 2-inch increments through this range, so an 18-inch round duct is the equivalent selection; going smaller raises velocity and friction loss.

5When installing flexible air ducts, what is the maximum allowable sag permitted per foot of distance between support hangers according to SMACNA and IMC guidelines?

A.1/2 inch per foot

B.1 inch per foot

C.1/4 inch per foot

D.2 inches per foot

Explanation: SMACNA Flexible Duct Performance & Installation Standards and IMC Section 603 specify that flexible duct supports must keep sag to a maximum of 1/2 inch per foot of support spacing. Excess sag restricts airflow and creates turbulence.

6According to the International Mechanical Code (IMC Section 603.6), what is the maximum permitted length of a flexible air connector used in branch supply runs?

A.8 feet

B.14 feet

C.20 feet

D.6 feet

Explanation: IMC Section 603.6.2.1 states that flexible air connectors shall not exceed 14 feet in length and shall not pass through any wall, floor, or ceiling. Flexible air ducts (UL 181 Class 1) are limited in length to ensure system integrity.

7External duct insulation installed on supply air ducts carrying chilled air through an unconditioned attic must feature a vapor retarder jacket with a maximum water vapor permeance rating of:

A.0.50 perms

B.0.10 perms

C.0.05 perms

D.1.00 perm

Explanation: SMACNA and energy conservation codes specify that external duct insulation installed on cooling supply air ducts in unconditioned spaces must have a factory-applied vapor retarder facing with a maximum permeance rating of 0.05 perms (tested per ASTM E96). This prevents moisture condensation on the cold duct surface.

8Which SMACNA duct sealing class requires sealing ALL transverse joints, longitudinal seams, and duct wall penetrations regardless of static pressure class?

A.Seal Class C

B.Seal Class B

C.Seal Class D

D.Seal Class A

Explanation: SMACNA Seal Class A is the highest sealing level, requiring sealant application to all transverse joints, longitudinal seams, and duct wall penetrations. It is required for high-pressure systems and all supply/return ducts located outdoors or in unconditioned spaces.

9Which type of longitudinal lock seam is continuously machine-formed along the helical length of round spiral ductwork?

A.RL-1 continuous spiral lock seam

B.Grooved lock seam (piping seam)

C.Snap-lock seam (button lock)

D.Standing seam lock

Explanation: Spiral round ductwork is manufactured using an RL-1 continuous helical spiral lock seam. This interlocked four-ply seam provides high structural rigidity and burst strength, allowing thinner metal gauges to withstand high static pressures.

10An air handling unit delivers 2,400 CFM through a 24-inch by 12-inch main supply trunk duct. What is the average air velocity inside the duct in feet per minute (FPM)?

A.1,000 FPM

B.1,200 FPM

C.1,400 FPM

D.1,600 FPM

Explanation: First find the duct cross-sectional area in square feet: (24 in x 12 in) / 144 = 288 / 144 = 2.0 sq ft. Then velocity V = Q / A = 2,400 CFM / 2.0 sq ft = 1,200 feet per minute. That sits in the normal 1,000 to 1,500 FPM range for a commercial main trunk.

About the AZ ROC C-45 Sheet Metal Exam

The Arizona ROC C-45 Sheet Metal Examination is a computer-delivered, open-book trade examination administered by PSI Services LLC for the Arizona Registrar of Contractors. The exam tests practical and technical knowledge of HVAC duct design and fabrication (SMACNA), chimneys, flues, and appliance venting, HVAC equipment and dampers, architectural metal flashing and roofing, gutters and downspouts, and OSHA 1926 construction safety standards.

Questions

30 scored questions

Time Limit

75 minutes

Passing Score

70%

Exam Fee

$66 (Arizona ROC / PSI Services LLC)

AZ ROC C-45 Sheet Metal Exam Content Outline

27%

Ducts

Duct design, sizing, fabrication, gauge requirements, joints, seams, hangers, insulation, static pressure classification, leakage testing, and SMACNA HVAC Duct Construction Standards.

17%

Chimneys, Flues, and Vents

Category I-IV appliance venting, Type B and Type L double-wall vents, chimney liners, draft hoods, clearances to combustibles, roof terminations, NFPA 54 / International Fuel Gas Code standards.

20%

Hoods, Ventilation, and Food Service Equipment

Exhaust fans, blowers, air handling units, dampers (fire, smoke, volume, backdraft), louvers, diffusers, grilles, air balance hoods, and mechanical equipment mounting.

13%

Metal Roofing Systems, Flashing, and Architectural Metals

Roof flashing, counterflashing, coping, expansion joints, metal roof panels, valley flashing, gravel stops, reglets, and SMACNA Architectural Sheet Metal Manual details.

10%

Gutters and Downspouts

Sizing rainfall runoff, gutter profiles (K-style, half-round, box), pitch/slope requirements, expansion joints, outlet tubes, conductor heads, splash blocks, and downspout hangers.

13%

OSHA Safety

OSHA 29 CFR 1926 standards for sheet metal workers, fall protection, ladder safety, personal protective equipment (PPE), shear/press brake guarding, hazardous material handling, and scaffold safety.

How to Pass the AZ ROC C-45 Sheet Metal Exam

What You Need to Know

Passing score: 70%
Exam length: 30 questions
Time limit: 75 minutes
Exam fee: $66

Keys to Passing

Work through all 100 available questions
Review every answer and explanation
Track weak areas and revisit them
Use our AI tutor for tough concepts

AZ ROC C-45 Sheet Metal Study Tips from Top Performers

1Master SMACNA duct gauge tables, transverse joint types (S-and-drive, standing S, pocket lock, companion flanges), and hanger spacing based on duct dimensions and gauge.

2Understand static pressure classifications (1 in. w.g., 2 in. w.g., 4 in. w.g., 10 in. w.g.) and duct reinforcement rules for high-pressure systems.

3Review appliance venting requirements under NFPA 54 / IFGC, focusing on Type B gas vent clearances (1 inch to combustibles), slope requirements (minimum 1/4 inch per foot), and termination height above roof surfaces.

4Study architectural sheet metal details, including thermal expansion calculations for metal roofing/flashing, counterflashing reglets, coping cap slope, and soldering techniques for copper/galvanized sheet metal.

5Memorize OSHA 1926 regulations for sheet metal work: fall protection requirements above 6 feet, point-of-operation guarding on power shears and press brakes, and eye protection requirements for cutting/welding.

Frequently Asked Questions

How many questions are on the official Arizona ROC C-45 Sheet Metal exam?

The official PSI C-45 Sheet Metal exam contains 30 scored multiple-choice questions. Candidates are allotted 75 minutes to complete the test.

What passing score is required for the AZ ROC C-45 exam?

A minimum passing score of 70% (21 correct out of 30 questions) is required to pass the trade exam.

Is the Arizona ROC C-45 Sheet Metal exam open book?

Yes, the examination is open-book. Approved references (such as SMACNA HVAC Duct Construction Standards, SMACNA Architectural Sheet Metal Manual, International Mechanical Code / IFGC, and OSHA 29 CFR 1926) may be brought into the PSI test center.

What topics carry the highest weight on the exam?

Ducts carries the highest weight at 27% (8 questions), followed by Equipment at 20% (6 questions), Chimneys, Flues, and Vents at 17% (5 questions), Architectural Metals at 13% (4 questions), OSHA Safety at 13% (4 questions), and Gutters and Downspouts at 10% (3 questions).

Where can I schedule the AZ ROC C-45 Sheet Metal exam?

Examinations are scheduled online through PSI Services LLC at https://test-takers.psiexams.com/azcon or by phone with PSI candidate services.

100+ Free AZ ROC C-45 Sheet Metal Practice Questions

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