AWS D1.1 is the American Welding Society’s structural welding code for steel—the standard that governs how load-bearing steel is welded, inspected, and accepted across most industrial construction and equipment. When a shop says its welders are D1.1 certified, it means those welders passed controlled performance tests proving they can produce sound structural welds in the positions and processes the certification covers.
What does the D1.1 code actually cover?
The code addresses the full life of a structural weld: joint design, qualified welding procedures, welder performance qualification, workmanship, and inspection and acceptance criteria. In short, it defines both how the weld should be made and how to prove it was made correctly. The American Welding Society maintains and updates the code.
Why should equipment buyers care about welder certification?
Because structural welds fail where nobody can see the shortcuts. Mezzanines, machine bases, lifting frames, platforms, and support steel all depend on weld quality that a coat of paint hides completely. Certification does not guarantee every weld—but it establishes that the people making your welds have demonstrated the skill under witnessed test conditions.
What is the difference between D1.1 and D1.6?
D1.1 governs carbon (structural) steel; AWS D1.6 is the parallel code for stainless steel. Shops that fabricate both materials—as we do for plants across Wisconsin and the Midwest—maintain welders certified to both, so each material is welded to the code written for it.
Does certified welding cost more?
The welding itself is not priced by the certificate. What costs money is the discipline around code work: qualified procedures, fit-up standards, and inspection requirements the project specifies. Our post on fabrication cost and lead time explains how inspection levels move a quote.
What should you ask a fabricator before structural work?
- Are your welders certified to AWS D1.1 (and D1.6 for stainless)?
- Will the work follow qualified welding procedures?
- What inspection is included, and what can be added if the project requires it?
- Who is responsible for weld records if the project needs documentation?
A capable shop answers these directly—the answers tell you more than any brochure.
What is a welding procedure specification (WPS)?
A WPS is the written recipe for a weld: base material, filler, process, positions, and the parameters proven to produce sound results. Under D1.1, procedures are qualified—demonstrated and documented—before production welding begins, and welders work to the WPS rather than personal preference. For a buyer, the WPS is what makes quality repeatable across different welders and different days.
How is a structural weld actually inspected?
It starts with trained visual inspection against the code’s acceptance criteria—profile, size, undercut, and surface discontinuities. Where the project requires more assurance, nondestructive examination methods can look beneath the surface. The right level depends on what the weld carries and what the specification demands; the key is deciding the inspection level at quote time, not after the steel is painted.
What documentation should a buyer expect from code work?
At minimum: confirmation that welders were qualified for the work performed, the procedures used, and the inspection results the project specified. On documented jobs this becomes a package your records keep for the life of the structure. If a shop cannot say plainly what records you will receive, that is your answer about how the work will be run.
Frequently asked questions
It depends on the project, jurisdiction, and specification. Many industrial and structural projects require it contractually; buyers should confirm what their specification calls for.
Welder qualifications must be maintained through continuity of work in the process; lapses require requalification. Reputable shops track this internally.
The code targets structural steel above thin-gauge thickness. Thin sheet work falls under different standards and practices.
Yes. Structural repairs, machine-base modifications, and plant alterations benefit from the same code discipline as new fabrication.
Often the quotes are closer than expected—the discipline is in how the shop already works. The expensive version is discovering an uncertified weld problem after installation.
Put certified welders on your structural work
A & P Fabricating Solutions, LLC maintains AWS D1.1 and D1.6 certified welders at our Appleton, Wisconsin shop, serving manufacturers across the Midwest. Send your structural project to the quote request page and we will review the welding and inspection requirements with you.
