§0.3 · Body of knowledge
CWI study guide
The CWI body of knowledge, laid out like a code book: four chapters, eleven Part A clauses, and concept pages for the pairs candidates mix up. The minimum percentages come from AWS B5.1:2025. Fact sheets, the certification route and the comparisons are linked at the bottom of this study guide.
- Exam
- CWI
- Chapters
- 4
- Clauses
- 11
- Concepts
- 15
0.3.1Three parts, three ways to study
Part A is the closed-book part, and it's where this guide spends its time. You know what a term means, what a symbol calls for and which method finds a subsurface crack, or you don't. Part B is hands-on: you measure replica welds with gauges and check them against the Book of Specifications. Part C is open book, so the skill there is finding the right clause in your code fast.
The reading behind Part A is AWS's own: the Welding Inspection Technology textbook and workbook, A3.0 for terms, A2.4 for symbols and B1.10 for NDE. The AWS one-week seminar ships A2.4:2020, A3.0:2020 and B1.10:2016 along with the D1.1 code (AWS CWI 1-Week In-Person Seminar page, checked October 2026). This site names those books. It doesn't reproduce them.
0.3.2Part A minimums by clause
Each bar is the minimum percentage of Part A that AWS B5.1:2025, Table 8.1 sets for that clause. The published minimums add up to 82% and the rest of the form is unallocated, so read every bar as a floor.
0.3.3The four chapters
Reading the job
Start with terms and definitions and welding and NDE symbols. Together they carry at least 22% of Part A, and every other clause leans on them. With symbols the traps are about placement: which side of the reference line, which side of the weld symbol a dimension sits on. The fillet weld symbol and groove weld symbols pages take those apart.
Making the weld
Joining and cutting processes carries the largest minimum, at least 14%: process choice, polarity, electrode designations, thermal cutting. The self-shielded vs gas-shielded flux core page covers one pair that gets swapped. Welding application and control is what the welder does with heat, position and sequence. Heat control and metallurgy is home to preheat vs interpass temperature and hot vs cold cracking. Welding calculations is short arithmetic with unit traps; heat input and fillet size vs throat are the two to own.
Judging the weld
Visual examination is about naming what you see and knowing when it becomes rejectable. Four concept pages hang off it: porosity, undercut vs overlap, incomplete fusion vs incomplete penetration and discontinuity vs defect. NDE methods asks which method suits which job, and MT vs PT and RT vs UT are the selection calls. Destructive testing has the smallest minimum, at least 3%: which test shows which property.
Paperwork and authority
Welder and procedure qualification is where WPS vs PQR sits: the instructions, the record that backs them, and the welder's own test record. Inspector duties covers what you check before, during and after welding, who has the final word, and the inspection gauges you'll also handle on Part B.
0.3.4Which book backs which clause
| Clause | Book to lean on | Minimum on Parts B and C |
|---|---|---|
| Terms and definitions | AWS A3.0 | No separate weight |
| Welding and NDE symbols | AWS A2.4 | No separate weight |
| Processes, application, metallurgy, calculations | Welding Inspection Technology | No separate weight |
| Visual examination | Welding Inspection Technology, then your code's visual acceptance clause | At least 34% of Part B (inspection and discontinuities) |
| NDE methods | AWS B1.10 | At least 8% of Part B (NDE application) |
| Destructive testing | Welding Inspection Technology | At least 8% of Part B (destructive testing and properties) |
| Qualification | Your code's qualification clause (Clause 6 in D1.1:2020 and D1.1:2025) | At least 28% of Part B and 25% of Part C |
| Inspector duties | Welding Inspection Technology and AWS B5.1 | No separate weight |
Minimums: AWS B5.1:2025, Table 8.1, minimum percentages within each part, checked October 2026. Part C also sets at least 25% each for fabrication and inspection, which fall on whichever code you chose.
0.3.5Every clause and concept
Clauses run in chapter order. Each concept sits under the clause it belongs to.
§1Reading the job
§2Making the weld
§3Judging the weld
§4Paperwork and authority
- 4.1Qualification
- 4.1AWPS vs PQR
- 4.2Inspector duties
- 4.1Qualification
0.3.6One way to work through it
Get the vocabulary down
Terms and symbols first. The flashcards drill the words; the two clause pages drill the questions.
Take one clause at a time
Read the clause page, run its tags, then read the remarks on every miss before moving on.
Mix the clauses
Run the practice test on all areas. Clauses that slip once they stop being labeled are the ones to revisit.
Put it on the clock
Sit the mock exam closed book. With a date booked, the CWI study plan slots the mocks in for you.
0.3.7Exam fact sheets
Numbers with a source and a check date: the exam format, the Part B practical, the Part C code book, fees, dates and results.
0.3.8Getting certified
Eligibility, the vision test, renewal at years 3 and 6, and endorsements. Start with how to become a CWI.
0.3.9Side by side
Comparisons without verdicts: CWI vs CSWIP 3.1 for the UK-based scheme, and CWI prep compared for seminars, books and practice tools.
0.3.10Sources
- AWS B5.1:2025 — minimum percentages for Parts A, B and C, in its Table 8.1 (checked October 2026)
- AWS CWI Examination User Guide, September 2026 — exam order and delivery (checked October 2026)
- AWS Exam References and Editions Guide, August 2025 — Part C code editions (checked October 2026)
- AWS CWI 1-Week In-Person Seminar page — books in the seminar kit (checked October 2026)
Take it off the desk
Our CWI prep app has practice questions for iPhone and iPad, for the days you can't sit at a screen.