AWS CWI Exam: Complete Study Guide with Practice Questions (2026)

The AWS Certified Welding Inspector (CWI) certification is the gold standard for welding inspectors worldwide. It's recognized across construction, oil and gas, manufacturing, and structural steel industries — and it's a prerequisite for many senior inspection roles. The exam is notoriously challenging, with a pass rate that hovers around 30% for first-time candidates.

This guide breaks down the exam structure, the key topics you must master, and a study plan that will get you ready in 3–4 months.

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AWS CWI Exam Structure

The CWI exam consists of three parts, all administered in a single day:

Part A — Fundamentals (Closed Book)

• 150 multiple-choice questions
• 2 hours to complete
• Passing score: 72%
• Covers welding fundamentals, inspection concepts, and general knowledge
• Topics: welding processes, metallurgy, NDE methods, weld joints, symbols, blueprints, codes

Part B — Practical (Hands-On)

• 46 questions based on a provided weld specimen kit
• 2 hours to complete
• Passing score: 72%
• Tests your ability to measure weld dimensions, identify defects, and use inspection tools
• You'll use micrometers, weld gauges, and a provided code book to evaluate sample welds

Part C — Open Book (Code Application)

• 46 questions based on AWS D1.1
• 2 hours to complete
• Passing score: 72%
• Tests your ability to navigate AWS D1.1 and apply its requirements
• You must bring your own printed copy of AWS D1.1 (current edition)

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Key Topics for Part A — Fundamentals

Part A is the broadest and most knowledge-intensive section. Here's what to focus on:

Welding Processes (≈25% of Part A)

• SMAW, GMAW, GTAW, FCAW, SAW — characteristics, applications, variables
• Heat input calculations
• Polarity and current types
• Shielding gases and fluxes

Welding Metallurgy (≈15%)

• Phase diagrams and solidification
• Heat-affected zone (HAZ) characteristics
• Preheat and interpass temperature control
• PWHT and stress relief
• Hydrogen-induced cracking and prevention

NDE Methods (≈15%)

• Visual testing (VT) — the primary CWI tool
• Radiographic testing (RT) — film interpretation basics
• Ultrasonic testing (UT) — straight and angle beam
• Magnetic particle (MT) and dye penetrant (PT) testing
• Acceptance criteria per AWS D1.1 Clause 8

Weld Joints and Symbols (≈10%)

• Joint types: butt, lap, tee, corner, edge
• AWS welding symbols (reference, arrow side, other side, supplementary)
• Groove weld geometry (root opening, bevel angle, groove angle)

Inspection and Documentation (≈15%)

• WPS/PQR/WPQ review
• Essential variables vs. non-essential variables
• Welder qualification and continuity
• Inspection reports and documentation

Codes and Standards (≈10%)

• AWS D1.1 structure and key clauses
• ASME B31.3 and API 570 overview
• ISO standards overview

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Key Topics for Part B — Practical

Part B tests hands-on inspection skills using a provided kit. You'll receive:

• A weld specimen with known dimensions
• Micrometers, cam gauges, and weld measuring gauges
• A copy of AWS D1.1 (provided for this section)

Key skills to practice:

• Measuring weld reinforcement, undercut, convexity, and fillet weld leg/throat
• Using a cam gauge and fillet weld gauge correctly
• Identifying surface defects visually
• Determining weld acceptance per D1.1 Clause 8 (Table 8.1)
• Reading and interpreting welding symbols on drawings

Pro tip: Buy a practice weld gauge kit and measure real welds before the exam. The muscle memory of using a cam gauge and fillet weld gauge is essential — you can't learn it from a book.

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Key Topics for Part C — Open Book (AWS D1.1)

Part C tests your ability to find information in AWS D1.1 quickly. The key is knowing the structure of the code:

Clause	Content
1	General Requirements
2	Design of Welded Connections
3	Prequalification of WPS
4	Qualification
5	Fabrication
6	Inspection
7	Stud Welding
8	NDT Requirements
9	Tubular Structures

Tab your code book with clearly labeled tabs for each clause and for the most frequently referenced tables:

• Table 3.1 (Prequalified WPS)
• Table 4.1 (Essential Variables)
• Table 5.1 (Preheat/Interpass)
• Table 8.1 (Acceptance Criteria — visual)
• Table 8.2 (Acceptance Criteria — NDE)

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12-Week Study Plan

Weeks 1–4: Fundamentals Foundation

Study welding processes, metallurgy, and NDE methods. Use the AWS CWI Seminar materials or a study guide like Welding Inspection Technology (WIT). Take practice quizzes after each topic.

Weeks 5–8: Code Mastery

Read AWS D1.1 cover to cover. Tab every clause. Practice looking up specific requirements — start with Clause 2 (design) and Clause 8 (acceptance criteria). Use the SkillJet.co welding simulator to practice code-based questions.

Weeks 9–10: Practical Skills

Buy or borrow a weld gauge kit. Practice measuring fillet welds, groove welds, and plate dimensions. Watch YouTube tutorials on using cam gauges and hi-lo gauges. The practical exam is where many candidates fail — don't neglect it.

Weeks 11–12: Full Mock Exams

Take full-length practice exams for all three parts. The SkillJet.co final certification mock exam mirrors the real format: timed, no instant feedback, auto-submit. Aim for 80%+ on all three parts before sitting for the real exam.

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Sample Practice Questions

Question 1 (Fundamentals)

Which of the following is an essential variable for SMAW?

• A) Travel speed
• B) Electrode diameter
• C) Both A and B
• D) Neither A nor B

Answer: C — Both travel speed and electrode diameter are essential variables for SMAW per AWS D1.1 Table 4.1.

Question 2 (Code — D1.1)

Per AWS D1.1 Table 8.1, what is the maximum allowable undercut for a statically loaded nontubular connection?

• A) 1/32 inch
• B) 1/16 inch
• C) 1/8 inch
• D) No undercut permitted

Answer: B — For statically loaded connections, undercut shall not exceed 1/16 inch. For cyclically loaded connections, the limit is 1/32 inch.

Question 3 (Practical)

When measuring a fillet weld with equal legs of 1/4 inch, what is the theoretical throat?

• A) 0.125 in
• B) 0.177 in
• C) 0.250 in
• D) 0.354 in

Answer: B — Theoretical throat = leg × sin(45°) = 0.25 × 0.707 = 0.177 inches.

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Common Mistakes to Avoid

1. Underestimating Part B — Many candidates focus on Part A and C, then fail the practical. Practice with real gauges.
2. Not tabbing D1.1 — In Part C, you have 2 hours for 46 questions. Without tabs, you'll waste time searching.
3. Ignoring math questions — Heat input, throat calculations, and thickness conversions are easy points if you've practiced.
4. Not taking a prep course — The AWS CWI seminar is highly recommended. Self-study alone has a lower pass rate.

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Start Your CWI Preparation

The AWS CWI exam is challenging, but with 3–4 months of structured study and realistic practice, you can pass on your first attempt. Start with a free diagnostic on SkillJet.co to assess your current knowledge, then drill your weak areas before taking the final certification mock exam. When you consistently score 80%+, you're ready for the real thing.