How AWS D1.1 is organized, and how to navigate it on CWI Part C

CWI Part C for the structural steel endorsement is an open-book test, and open book does not mean easy. It means the exam is measuring one skill: how fast you can find the right clause in AWS D1.1 and apply it correctly under a clock. Candidates who fail Part C rarely fail because they do not know welding. They fail because they burn four minutes hunting for a table that a practiced navigator flips to in fifteen seconds. This guide maps how the code is organized so you can build that speed. It describes structure only: we never reproduce the copyrighted code text, which stays your own purchase from AWS. For which edition to buy, see the code book and edition hub; to decide whether D1.1 is even the right endorsement for your work, see the D1.1 endorsement guide.

The shape of the book: 10 clauses in a deliberate order

AWS D1.1/D1.1M is arranged into ten numbered clauses, and the order is not arbitrary. It walks from the general to the specific, then from making a weld to judging one:

1. General Requirements. Scope, the base metals and thickness range the code governs, responsibilities, and where the major definitions and symbols are anchored.
2. Normative References. The other standards D1.1 pulls in by reference.
3. Terms and Definitions. Where you resolve what a term means when a question hinges on a precise definition.
4. Design of Welded Connections. Effective throat, allowable stresses, and the joint design rules. This is the engineering clause.
5. Prequalification of WPSs. The prequalified joint-detail figures, the prequalified base-metal and filler-metal combinations, and the preheat and interpass tables. This is where “is this joint prequalified?” is answered.
6. Qualification. How a welding procedure, and how a welder or operator, becomes qualified: the tests, the positions, and the ranges a given test qualifies.
7. Fabrication. Workmanship: fit-up, tolerances, arc strikes, tack welds, and the preparation and repair rules.
8. Inspection. Inspector responsibilities and, critically, the visual and nondestructive acceptance criteria. This is the acceptance clause.
9. Stud Welding.
10. Tubular Structures.

Behind the clauses sit the annexes (normative forms and informative guidance), a commentary, and an alphabetical subject index. In the 2020 edition the clause numbering above is exactly what you will see; because the CWI D1.1 exam is written to apply to either the 2020 or the 2025 edition, confirm the clause numbers in the edition you actually bring, since a code revision can shift a clause or a table number.

The three clauses that answer most Part C questions

You do not need to know all ten clauses equally. Structural Part C questions cluster hard into three of them, and knowing which question type lives where is most of the battle.

• “Is this weld acceptable?” lives in the Inspection clause (Clause 8). The visual acceptance criteria are a table keyed to whether the connection is statically loaded or cyclically loaded, so the first thing to read in the stem is which loading condition applies, because the same discontinuity can pass one and fail the other. The nondestructive acceptance criteria for radiography and ultrasonic testing also sit in this clause. When a question hands you a discontinuity size and asks accept or reject, you should be turning to Clause 8 on reflex.
• “Is this joint prequalified?” lives in the Prequalification clause (Clause 5). The prequalified groove and fillet joint details are a large set of figures, and questions that give you a joint geometry and ask whether it may be used without qualification testing are answered by matching the geometry to those figures and their limits. The prequalified preheat and interpass minimums also live here.
• “Does this procedure or welder qualify for that?” lives in the Qualification clause (Clause 6). Questions that give you a test plate thickness, position, or process and ask what range it qualifies are resolved by the qualification tables in this clause.

Design questions send you to Clause 4, workmanship-tolerance questions to Clause 7, but the three above are where the clock is won or lost.

Building navigation speed before exam day

The fast navigators do three things, and none of them involve reading the code cover to cover:

1. Tab the clause dividers and the acceptance table. A physical, tabbed book you have handled is worth far more on Part C than a pristine one. Confirm with your test center what form of the book and what tabbing is permitted before you rely on it.
2. Practice from the stem backward. Read a practice question, decide which of the three home clauses it belongs to before you open the book, then verify. The skill being trained is classification, not reading speed.
3. Learn the index and table of contents as tools. When a question uses a term you cannot place, the alphabetical index at the back is faster than paging. Knowing the book has an index, and using it, separates candidates who finish from candidates who run out of time.

A realistic Part C plan pairs this navigation drilling with the closed-book fundamentals of Part A and the format practice of Part B; the full three-part study plan is in the exam guide, and the honest part-by-part difficulty read is in how hard is the CWI exam.

Buy the right edition, then learn to move through it

Owning D1.1 is only useful if it is the edition your exam is pinned to; bringing last year’s printing is a classic and expensive Part C mistake. The current pinned editions for every endorsement, including the two D1.1 editions the exam applies to, are in the code book and edition hub, and you can compare D1.1 against the pipeline and ASME code books there before you spend the money. If your work is not actually structural steel, the endorsement recommender points you at the code your inspections are really judged against so you navigate the right book on exam day.

Sources: the AWS Certified Welding Inspector endorsement pages and the AWS Exam References and Editions Guide (last updated August 1 2025), checked 2026-07-24, plus the public table-of-contents structure of AWS D1.1/D1.1M. This page describes the organization of the code only and reproduces no code text; the code book itself is your own purchase from AWS. Clause and table numbering can change when a code edition is reissued, so confirm the arrangement in the specific edition your exam is administered to. This site is independent, is not affiliated with AWS, and sells no seminar, course, or code book.