CWI Part C: how to pass the D1.1 code book exam

CWI Part C is an open-book exam on the code you choose, most often AWS D1.1 (Structural Welding Code, Steel). AWS gives 50 to 60 scored questions in 120 minutes, or 135 minutes when your form includes about 5 unscored pretest items, and you need 72% to pass (AWS Part C exam information). That is about two minutes per question, so the skill being tested is finding the right clause or table fast.

This page covers how the exam is set up, how to tab your code book, a lookup method for each question, and how to practice.

Part C at a glance

Sources: AWS Part C exam information (Rev. 02.11.2025) and the AWS Examination User Guide for CWI. AWS's CWI page lists D1.1:2025-AMD1 as the current standard, so check which edition your exam uses before you buy a book.

D1.1 is one of several Part C code choices. AWS's CWI page also lists API 1104, D1.2, D1.5, D15.1, D17.1, ASME Section IX with B31.1 and B31.3, and an ISO option. This page is about D1.1. For what "D1.1 certified" means for welders and the D1.1 endorsement, see AWS D1.1 certification.

Where the questions come from

AWS sets minimum shares for Part C: at least 25% each on qualification, fabrication and inspection, and at least 5% each on reports and records and on materials and design. In D1.1:2020, those topics map onto clauses 4 to 8.

If you learned on D1.1:2015, note that the 2020 edition moved most clauses. For example, inspection was Clause 6 in 2015 and is Clause 8 in 2020, and qualification moved from Clause 4 to Clause 6. Old notes and old practice sets will point you to the wrong place.

Our four Part C study guides walk through each area:

• D1.1 qualification (Clauses 5 and 6)
• D1.1 fabrication (Clause 7)
• D1.1 inspection (Clause 8)
• D1.1 design, materials and records (Clauses 1 to 4)

How to tab your code book

Tabs are the biggest time saver you can bring into Part C. A simple system that works:

1. One color for clauses. Put a tab at the start of each clause, 1 to 11, labeled with the number and a short name. You will use these to get to the right part of the book in seconds.

2. A second color for tables and figures you will use often. For D1.1, that usually means the visual inspection acceptance criteria (Table 8.1 in 2020), the prequalified base metal and filler metal tables, the preheat table, the minimum fillet weld size table, the WPS and welder qualification tables in Clause 6, the electrode exposure table, the weld profile figures and the tolerance figures.

3. Keep the labels short. "8.1 VT accept" is faster to read than "Visual inspection acceptance criteria."

4. Highlight the conditions, not the numbers. Many wrong answers come from reading the right table under the wrong condition. Highlight words like statically loaded, cyclically loaded, tubular and nontubular where they change which column applies.

5. Write cross-references in the margin. If a table note sends you to another subclause, write that subclause number next to the note.

If your exam uses an on-screen PDF instead of your book, tabs won't be available. In that case, practice with the PDF's search and bookmarks, and learn the clause order by heart so you know where to jump.

A 4-step method for each question

1. Read the last line first. Is it asking for a number, a yes or no on acceptance, or who is responsible?
2. Name the conditions. Statically or cyclically loaded? Tubular or nontubular? Prequalified or qualified by test? Which process? These decide the clause, the table and the column.
3. Go to the clause, then the table. Use your clause tab, then your table tab. Read the table's title and notes before the cells.
4. Check the units and the note. D1.1 gives values in both inches and millimeters. Many distractors are the right number from the wrong column or the wrong unit.

If a question takes more than about three minutes, mark it and move on. Easy questions are worth the same as hard ones.

How to practice

• Use your own tabbed book from day one, so you practice the same moves you will make in the exam.
• Time yourself. Give yourself two minutes a question and note which ones ran over. Those show where you need a better tab.
• Don't memorize values. Practice the path to them. On the exam, the question may use a different thickness or process than your practice set.
• Learn the clause order. You should be able to say, without looking, which clause covers fabrication or stud welding.

Our free Part C practice questions are written for D1.1:2020. Each one gives the clause or table to look in, and none of them quote the code. The free CWI diagnostic has a Part C option, 25 questions on D1.1:2020, so you can test your lookup speed before you pay for anything.

Frequently asked questions

Is CWI Part C open book?

Yes. Part C is open book. AWS's user guide says you may use tabs, highlighting and margin notes in your code book. Some Part C exams provide the code only as an on-screen PDF, so check your exam details before test day.

How many questions are on CWI Part C?

AWS's Part C information lists 50 to 60 scored questions. Selected English forms add about 5 unscored pretest items, for 55 to 65 in total.

How long is CWI Part C?

120 minutes without pretest items, and 135 minutes when your form includes them. That is about two minutes per question.

Which edition of D1.1 is used for CWI Part C?

AWS's current Part C exam information names AWS D1.1/D1.1M:2020. AWS also sells the newer D1.1:2025 edition, so the exam may change. Check AWS's current Part C guide before you buy your code book.

Can I write notes in my code book for Part C?

AWS's Examination User Guide says tabs, highlighting and margin notes are allowed.

What is the passing score for Part C?

72%. You also need a 72% composite score across all three parts of the CWI exam.

Sources

Our D1.1 Inspection questions cite these documents, by document and, where we can confirm it, chapter or section.

1. AWS D1.1 (42 questions)

Questions? support@cwiready.com