CWI Part A Exam Study Guide (2026)
Everything the AWS CWI Part A Fundamentals Exam (Certified Welding Inspector) tests, topic by topic: what each section covers, the facts that come up most, and how to study it. Pair it with the free 15-question practice test.
The exam at a glance
| Questions | 150 scored multiple-choice questions plus 15 unscored pretest items (165 in total) |
|---|---|
| Time | 135 minutes |
| Passing score | 72% on Part A (each of Parts A, B and C must be passed at 72%) |
| Format | Closed book, computer-based |
| Certifying body | American Welding Society (AWS) |
| Test provider | Prometric test center (computer-based) |
Mind map: the whole exam on one screen
Read the complete CWI Part A study notes for “Definitions, Terminology and Joint Design”
Our first full set of comprehensive notes, about 15 minutes of reading: Joints and weld types · Groove terms · Parts of a weld · Size versus throat · Welding positions, a worked exam example, the traps examiners use and a one-minute recap. Create a free account to read it and see how premium notes work before you decide.
1. Definitions, Terminology and Joint Design
The biggest content area on Part A (definitions and terminology, at least 12%). Learn the exact AWS A3.0 terms for joints, grooves, weld parts and welding positions, because many questions turn on one word.
Key facts
- The five basic joint types are butt, corner, edge, lap and T. Groove, fillet and plug are weld types, not joint types.
- Groove terms: root opening (the gap), root face (the land), bevel angle (one member), groove angle (the total included angle), groove face.
- A double-bevel groove angle is the sum of the two bevel angles. A 30° bevel on each member gives a 60° groove angle.
- Weld parts: face, root, toe (junction of the weld face and the base metal), leg, throat and reinforcement.
- Fillet weld size is the leg length of the largest inscribed right triangle. A convex fillet's size is the leg, not the actual throat.
- Theoretical throat of an equal-leg fillet is 0.707 times the leg. Effective throat is the minimum distance from the weld face, minus any convexity, to the weld root.
- Position numbers: 1 flat, 2 horizontal, 3 vertical, 4 overhead. G is groove, F is fillet. Pipe: 1G rolled, 2G axis vertical, 5G axis horizontal and fixed, 6G axis at 45° and fixed.
Flashcards
Exam tip: If two answers look alike, ask which word the question uses. Root face and root opening, undercut and underfill, groove and bevel: Part A loves the swap.
2. Welding Processes and Cutting
Welding processes (at least 12%) and cutting (at least 2%): how SMAW, GMAW, FCAW, GTAW and SAW work, their shielding, current and electrode classifications, and which cutting process suits which metal.
Key facts
- SMAW: flux-coated electrode, constant current, manual. The coating provides shielding, slag and alloy additions.
- GMAW and FCAW normally use constant-voltage power with wire feed. FCAW can be gas-shielded or self-shielded.
- GTAW uses a nonconsumable tungsten electrode with inert gas. DCEN is normal for steels; AC is used for aluminum.
- SAW has the arc hidden under granular flux. High deposition, but mostly flat and horizontal positions.
- GMAW transfer modes: short-circuiting, globular, spray and pulsed spray. Spray needs an argon-rich gas.
- E7018: 70 ksi minimum tensile strength, usable in all positions, low-hydrogen iron-powder coating, AC or DCEP. ER70S-6 is a solid wire or rod; E71T-1 is a tubular wire, usable in all positions.
- Oxyfuel cutting oxidizes iron, so it works on carbon and low-alloy steel, not stainless or aluminum. Plasma arc cutting handles those; air carbon arc uses a carbon electrode and compressed air to gouge.
Flashcards
Exam tip: For any process question, name four things: electrode, shielding, power type and typical positions. Most wrong options break one of the four.
3. Welding and NDE Symbols
AWS A2.4 welding and nondestructive examination symbols (at least 10%). The exam is closed book, so arrow-side rules, size and pitch placement and supplementary symbols have to be automatic.
Key facts
- Below the reference line means arrow side; above means other side; both sides mean both sides of the joint.
- Fillet: size to the left of the weld symbol, length and pitch to the right. Pitch is center-to-center.
- Groove: depth of bevel left, with groove weld size in parentheses, root opening inside the symbol and groove angle outside.
- A break in the arrow points to the member that is prepared (bevel or J).
- Supplementary symbols: flag for field weld, circle for weld all around, melt-through, backing and contour (flush, convex or concave) with finish letters such as G for grinding and M for machining.
- Tail holds the specification, process or other reference. With multiple reference lines, the line nearest the arrow is done first.
- NDE letters: RT, UT, MT, PT, VT, ET, LT and AET.
Flashcards
Exam tip: Draw the joint for every symbol question on your scratch paper: a two-second sketch beats reading the symbol twice.
Test yourself on these topics
Take the free 15-question CWI Part A test, then save your results to unlock your Readiness Score and the mistakes bank.
4. Weld Examination and Discontinuities
Weld examination (at least 10%): visual inspection before, during and after welding, and recognizing each discontinuity by its name, cause and appearance.
Key facts
- A discontinuity is an interruption in the structure. It becomes a defect only when it exceeds the acceptance criteria of the applicable code.
- Undercut is a groove melted into the base metal at the toe and left unfilled. Underfill is a weld face or root below the base metal surface.
Flashcards
Exam tip: On discontinuity questions, picture where it sits: surface or internal, toe or root, weld metal or base metal. That usually eliminates two options.
5. WPS, PQR and Welder Qualification
Welding performance (at least 9%): what a WPS, a PQR and a welder qualification record each do, what essential variables are and how qualification test positions work.
Key facts
- A WPS gives production directions, with ranges. A PQR records the actual values used in a test weld and the test results.
- A WPS must be supported by one or more PQRs, unless a code allows prequalified procedures.
Flashcards
Exam tip: Keep one rule in mind: a PQR is history, a WPS is the instructions. If the question says 'actual', 'recorded' or 'test results', think PQR.
6. Nondestructive Testing Methods
NDE test methods (at least 8%): what each method can find, what materials it works on and its limits. Expect questions that ask for the best method for a given situation.
Key facts
- VT is the first and cheapest method. It only sees surface conditions.
- PT finds discontinuities open to the surface on any nonporous material. Steps: clean, apply penetrant, dwell, remove excess, apply developer, inspect, clean.
Flashcards
Exam tip: Ask what the flaw is and what the metal is. Surface flaw on stainless: PT. Near-surface flaw on carbon steel: MT. Internal volumetric: RT or UT.
7. Metallurgy, Heat Control and Destructive Tests
Heat control and metallurgy of carbon and low-alloy steel (at least 6%) and destructive tests (at least 3%): preheat, hydrogen cracking, heat treatments and what each mechanical test measures.
Key facts
- Hydrogen cracking needs hydrogen, a susceptible hard microstructure such as martensite, and tensile stress.
- Preheat slows cooling, which reduces hardness and lets hydrogen escape. Higher carbon equivalent and thicker sections need more preheat.
Flashcards
Exam tip: Link each test to the property it measures. If the question asks about toughness, the answer is Charpy; if it asks about soundness, it's bend.
8. Calculations, Duties and Safety
Welding-related calculations (at least 6%) and duties and responsibilities (at least 4%), plus safety. These are quick marks: learn the formulas, unit conversions and the inspector's ethical duties.
Key facts
- Heat input (J/in.) = volts × amps × 60 ÷ travel speed (in./min).
- Tensile strength = load ÷ original area. Area of a round specimen = π × d² ÷ 4.
Flashcards
Exam tip: Write the heat input and tensile formulas on your scratch paper as soon as the exam starts. Then these questions take under a minute.
How to pass
- 165 questions in 135 minutes is just under 50 seconds each. Definition and symbol questions should take 20 seconds so you bank time for calculations.
- Definitions and terminology (12%) and welding processes (12%) are the two biggest content areas. Learn the exact AWS A3.0 terms: undercut vs. underfill, root face vs. root opening.
- Symbols are at least 10% of the exam and it's closed book. Practice reading AWS A2.4 welding and NDE symbols until arrow side vs. other side is automatic.
- 15 questions are unscored pretest items and you can't tell which. Treat every question as if it counts.
Frequently asked questions
How long should I study for the CWI Part A exam?
Most working candidates need 4 to 8 weeks at 45 to 60 minutes a day. Book your exam once your Readiness Score has stayed at 80 or higher for about a week.
Can I take the CWI Part A exam online?
AWS delivers Parts A and C on computer at Prometric test centers and Part B on paper at AWS-authorized exam sites. Its current guides don't describe remote proctoring. Format: closed book, computer-based. Check aws.org for updates.
What score do I need to pass the CWI Part A exam?
72% on Part A (each of Parts A, B and C must be passed at 72%). The exam has 150 scored multiple-choice questions plus 15 unscored pretest items (165 in total) and a time limit of 135 minutes.
What are the most tested topics?
The outline covers definitions, terminology and joint design, welding processes and cutting, welding and nde symbols, weld examination and discontinuities, wps, pqr and welder qualification, nondestructive testing methods, metallurgy, heat control and destructive tests, calculations, duties and safety. Use the free practice test to see which ones you need most.
The premium CWI Part A study path
Premium CWI Part A prep is studied one topic at a time. Each step starts with that topic's key notes and flashcard deck, then its own question sets of 25, so you master one topic before you move to the next. When every topic is strong, the 6 full mock exams show you're ready.
Your step-by-step study path
- 1Definitions, Terminology and Joint Design8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Notes free with an account
- 2Welding Processes and Cutting8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 3Welding and NDE Symbols8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 4Weld Examination and Discontinuities8 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 5WPS, PQR and Welder Qualification7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 6Nondestructive Testing Methods7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 7Metallurgy, Heat Control and Destructive Tests7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- 8Calculations, Duties and Safety7 key notes, 100 flashcards, then 375 practice questions in 15 sets of 25Premium
- Final step: 6 full mock exams150 questions each, timed like test day. Pass them, then book your exam.Premium
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Summarized from AWS's official candidate information and the rules cited, checked October 2026. Confirm current requirements with American Welding Society (AWS).