D1.1 Design, Materials and Records for CWI Part C

Where this area fits

AWS's Part C information guide sets minimums of 5% for materials and design and 5% for reports and records. That is fewer questions than qualification, fabrication or inspection. Many of them test whether you can find the right clause. Knowing the layout of the book does most of the work.

This guide covers the parts of D1.1 that the other three Part C guides do not. They are the general clauses, the design rules an inspector applies, base and filler metals, stud welding and records.

The clause map

D1.1:2020, the edition AWS lists for Part C, reorganized the code compared with 2015. Its clauses:

1. General Requirements.
2. Normative References.
3. Terms and Definitions.
4. Design of Welded Connections.
5. Prequalification of WPSs.
6. Qualification.
7. Fabrication.
8. Inspection.
9. Stud Welding.
10. Tubular Structures.
11. Strengthening and Repair of Existing Structures.

If your study notes use 2015 numbering, these are the main shifts:

• Design moved from Clause 2 to 4.
• Prequalification moved from 3 to 5.
• Qualification moved from 4 to 6.
• Fabrication moved from 5 to 7.
• Inspection moved from 6 to 8.
• Stud welding moved from 7 to 9.
• Tubular structures moved from 9 to 10.
• Existing structures moved from 8 to 11.
• Terms and definitions moved from an annex into Clause 3.

Navigation questions often ask which clause covers a topic. Examples are repair of an existing building (Clause 11) or where definitions are found (Clause 3).

Design rules an inspector uses

Clause 4 is written for the Engineer, but inspectors apply several of its limits when checking drawings and finished work. Most of them sit in the provisions on effective areas and on specific joint types.

Fillet welds

The fillet weld provisions cover:

• Effective length. What length counts in design, including whether boxing (end returns) counts.
• Minimum length. A minimum tied to the weld size; a shorter weld is credited with a smaller effective size.
• Maximum size along an edge. A limit tied to the material thickness, so the original edge stays visible for inspection. The exception is a drawing that calls for the weld to be built out to full throat.
• Intermittent fillets. Minimum segment length.

Worked example: a fillet weld runs along the edge of a 1/2 in. plate. The drawing does not call for it to be built out. For material 1/4 in. or thicker, the maximum is the thickness less 1/16 in., so the largest weld is 7/16 in.

Lap joints and groove welds

• The lap joint provisions set a minimum overlap based on the thinner part.
• The effective size of a CJP groove weld is the thickness of the thinner part joined. Reinforcement does not add to it. PJP groove welds have their own effective throat rules.

Loading type

Clause 4 separates statically and cyclically loaded design. That split carries through to Table 8.1, which has separate columns for each. Find the loading type before you judge a weld.

Materials

The base metals approved for prequalified WPSs, and the filler metals that match them, are in Clause 5 tables. To use them:

1. Find the steel specification and grade in the base metal table and note its group.
2. Go to the filler metal table, find that group and read the matching classifications for your process.

Worked example: a contractor wants to use a prequalified WPS on a steel that is not in the base metal table. It cannot, however close the strength is. The WPS must be qualified by test under Clause 6, which also has provisions for unlisted steels.

When an inspector checks materials, the questions to ask are:

• Is the base metal listed, or covered by a qualified WPS?
• Does the filler metal classification match the base metal group?
• Are mill test reports and filler metal certifications available, and do they match the material on hand?

Stud welding

Clause 9 (Clause 7 in 2015) covers stud welding. Its parts follow the work: stud requirements, application qualification, production control, fabrication and verification inspection.

Worked example: before production starts each day or shift, the production control provisions call for a check of the first studs welded. They are examined for a full weld flash and bent, and both must pass before production continues.

Reports and records

Records questions test whether you know who keeps what, and what the inspector must check before welding:

• The inspector reviews the WPSs, with supporting PQRs when they were qualified by test. The inspector also reviews the qualification records of the welders, welding operators and tack welders who will use them.
• The inspector keeps records of these qualifications and of other tests made.
• Parts or welds that the inspector has inspected and accepted must be marked, or recorded by another method.

D1.1 includes sample forms in an annex for WPSs, PQRs and welder qualification records. They are optional formats, but knowing their fields helps when a question shows a partial record and asks what is missing.

Study plan

1. Learn the 11-clause map and the 2015 to 2020 shifts.
2. Tab the fillet weld, lap joint and effective area provisions in Clause 4.
3. Tab the Clause 5 base metal and filler metal tables.
4. Skim Clause 9 so its parts are familiar.
5. Practice short navigation drills: name the clause for ten random topics in under a minute.

Mark J. Curry tip: look at the table of contents at the start of the exam. It reminds you of the clause order before the first question.

Common traps

• Using the thicker part for lap joint overlap or CJP weld size. Both rules use the thinner part.
• Forgetting the 1/16 in. reduction for fillets along edges 1/4 in. and thicker.
• Assuming a steel with similar strength to a listed grade can use a prequalified WPS.
• Looking for definitions in an annex because older notes say so.

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

Practice this domain

Sources

The D1.1 Design, Materials and Records questions cite these documents, by document and, where we can confirm it, chapter or section. We never reproduce them.

1. AWS D1.1 (15 questions)

Found a mistake? Use "Report a problem" under any question, and Mark J. Curry checks it.

Questions? support@cwiready.com