AWS CWI Exam Study Guide: How to Pass the Certified Welding Inspector Exam
Complete guide to the AWS Certified Welding Inspector (CWI) exam — the three-part structure, Part B code book open-book strategy, and how to prepare for Part A and Part C.
The Three-Part CWI Exam Structure
The AWS CWI exam consists of three parts taken in a single day: Part A (Fundamentals) — 150 closed-book questions covering welding processes, metallurgy, destructive and nondestructive testing, symbols, and safety. Part B (Practical) — open-book questions that require you to look up acceptance criteria, tolerances, and procedural requirements in your chosen welding code (D1.1, API 1104, ASME Section IX, or AWS D1.6). Part C (Code Book) — open-book questions from the specific welding code you selected. You must pass all three parts in the same sitting to earn certification.
Part A: What Fundamentals Actually Covers
Part A is the most technically broad section of the CWI exam. Expect questions on: welding processes (SMAW, GMAW, GTAW, FCAW, SAW) including electrode classifications and process parameters; weld discontinuities and their causes (porosity, undercut, incomplete fusion, overlap, cracks); metallurgy concepts (HAZ, grain structure, preheat requirements); nondestructive examination methods (VT, PT, MT, RT, UT, TOFD); welding symbols per AWS A2.4; destructive testing (bend tests, tensile, hardness); and OSHA safety basics. Budget 60% of your study time for Part A.
Tabbing Your Code Book for Part B and C
Part B and C are open-book, but time pressure is severe. For AWS D1.1 (Structural Steel), the most tested tables and figures are: Table 4.5 (Prequalified WPS parameters), Table 4.9 (Fillet weld sizes), Table 6.1 (Acceptance criteria for visual inspection), Table 8.1 (UT scanning patterns), and the prequalified joint details in Annex A. Tab these by name, not just page number. You need to find the answer to a code question in under 60 seconds. Practice running code lookups until it becomes automatic.
Eligibility Requirements
To sit for the CWI exam, you need documented education and welding experience. The minimum: a high school diploma or GED with 5 years of welding-related experience, of which at least 1 year must be in a welding inspection-related function. A welding technology degree can reduce the experience requirement to as little as 1 year. All experience must be documented on an AWS work history form and verified by a supervisor or HR. AWS is strict about documentation — missing signatures or vague job descriptions are common reasons applications are rejected.
How to Pass All Three Parts
Most candidates pass Part C (their code book) but struggle with Part A (fundamentals). Plan for 80–120 hours of total study. Use the AWS Welding Handbook as your primary reference for Part A fundamentals. For code-book practice, work through code-lookup exercises where you're given a scenario and must find the correct table or clause. The CWI Prep app includes 700+ questions across all three exam parts, organized by topic, so you can measure your readiness in each area independently before exam day.