Which CWI code books to buy, which edition, and why
Quick answer
Which code book and edition do I need for the CWI exam?
Each CWI endorsement is administered to one specific code book and a specific pinned edition, so you buy the book that matches your endorsement in the exact year AWS lists. The structural endorsement uses D1.1, pipeline uses API 1104, and the piping endorsement pins three ASME books at once. Buying the wrong edition is a common and expensive Part C mistake.
The open-book part of the AWS Certified Welding Inspector (CWI) exam, Part C, is administered to a specific edition of a specific code, and every endorsement pins its own book and its own year. The code books are your own purchase, they are expensive, and you cannot pass Part C with the wrong one, so buying the wrong book or the wrong year is one of the costliest and most common mistakes candidates make. This is the master buying guide: which book each endorsement needs, the exact edition AWS lists for the current exam window, and how to spend the money once.
The editions below are taken from the official AWS Exam References and Editions Guide, last updated August 1 2025, and were re-checked against the AWS endorsement pages on 2026-07-24. AWS can revise these when a new code edition is released, so confirm the edition on your own exam confirmation letter, which is the authoritative statement of what your specific exam is administered to, before you buy.
We publish which code and which edition each exam uses, because that is a fact. We never reproduce the copyrighted code text itself: that stays your own purchase from AWS, the American Petroleum Institute (API), or the American Society of Mechanical Engineers (ASME).
Endorsement code editions for the current exam window
| Endorsement | Code book | Edition AWS lists |
|---|---|---|
| Structural Steel (D1.1) | AWS D1.1 Structural Welding Code, Steel | AWS D1.1/D1.1M:2020 and :2025 (the exam is written to apply to either) |
| Structural Aluminum (D1.2) | AWS D1.2 Structural Welding Code, Aluminum | AWS D1.2/D1.2M:2014 |
| Bridge Welding (D1.5) | AWS D1.5 Bridge Welding Code | AASHTO/AWS D1.5/D1.5M:2020 |
| Railroad (D15.1) | AWS D15.1 Railroad Welding Specification | AWS D15.1/D15.1M:2019 |
| Aerospace (D17.1) | AWS D17.1 Fusion Welding for Aerospace Applications | AWS D17.1/D17.1M:2024 |
| Pipeline (API 1104) | API Standard 1104, Welding of Pipelines and Related Facilities | API 1104, 22nd Edition |
| ASME piping | ASME BPVC Section IX, ASME B31.1 Power Piping, ASME B31.3 Process Piping | Section IX 2023, B31.1 2024, B31.3 2024 |
Buy the book for the endorsement your work actually needs
The first decision is not the edition, it is the endorsement, because the endorsement dictates the book. If you inspect structural steel you buy D1.1; if you inspect cross-country pipeline you buy API 1104; if you inspect refinery or power-plant piping you buy the three ASME books. Buying a code for an endorsement you did not need is the most avoidable spend of all. If you are still choosing, the endorsement recommender maps your industry to the right code first, and each endorsement’s own decision guide, the structural D1.1 guide, the pipeline API 1104 guide, and the ASME piping guide, spells out the work each one unlocks before you spend anything on a book.
The D1.1 exam applies to two editions at once
The D1.1 line in the table carries two editions because AWS states the structural steel exam is designed to apply to either the 2020 or the 2025 edition. If you already own the 2020 edition you do not need to re-buy for that reason alone, but confirm on your own exam confirmation letter. Whichever of the two you bring, the skill Part C measures is navigation, not memory, so knowing how the book is arranged matters as much as owning it: the D1.1 navigation guide maps where the acceptance criteria, the prequalified joint details, and the qualification tables live.
The ASME piping endorsement pins three books at once
The combined ASME piping endorsement is the one that catches people out on cost, because it references three separate ASME publications, each a separate purchase: ASME Boiler and Pressure Vessel Code (BPVC) Section IX (2023), ASME B31.1 Power Piping (2024), and ASME B31.3 Process Piping (2024). The 60-question exam splits 26 questions on B31.1, 18 on Section IX, and 16 on B31.3. Budget for all three books, not one, and weight both your spending attention and your study toward B31.1, which carries the most questions. Because you are moving between three books under the clock, the routing skill is decisive: the three-book ASME navigation guide shows which keyword sends you to which book and where each book’s qualification, welding, and acceptance criteria sit. The pipeline API 1104 navigation guide does the same for the single pipeline book, including the standard-versus-alternative acceptance trap.
What Part B uses instead of a code book
The Part B practical is not a code exam. It is administered against the AWS Book of Specifications, a controlled document you use with a set of molded plastic weld replicas and inspection gauges at the test site. You do not buy a code edition for Part B; the Book of Specifications is provided for the exam. See the Part B practical walkthrough for what the kit contains.
Where to buy, and the format question
The code books are sold by their issuing bodies: AWS codes from AWS, API 1104 from the American Petroleum Institute, and the Section IX and B31 books from ASME. Prices vary by book and are set by the publisher, not by us, so buy from the source rather than a reseller offering an unnamed edition. One practical point worth settling before you buy: an open-book Part C is taken with a physical, tabbed book at the test center, and whether a printed copy, an electronic copy, or a particular form of tabbing is permitted is a test-center rule, so confirm the allowed format with AWS or your Prometric center before you commit to print or digital. The cost of the code book is only one line in the total; the full itemized, dated exam cost is on the cost table and in the cost calculator.
Buy the book once, and buy the right year
The single most expensive edition mistake is buying last year’s API 1104 or an older D1.1 printing and discovering it on exam day. Confirm the edition against your own AWS exam confirmation letter, which lists the editions your specific exam is administered to, then buy. Once you own the right book, the money is spent well only if you can move through it fast, which is why the navigation guides above matter as much as this table: the D1.1, API 1104, and three-book ASME walkthroughs turn a book you own into a book you can use under the clock.
Source: AWS Exam References and Editions Guide (last updated August 1 2025) and the AWS CWI and SCWI endorsement pages, checked 2026-07-24. This page describes which code and edition each exam uses and reproduces no code text; the code books themselves are your own purchase from AWS, API, and ASME. Editions can change when a code is re-issued; the date above is when each was last verified against the official source. This site is independent, is not affiliated with AWS, API, or ASME, and sells no seminar, course, or code book.