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D1.1/D1.1M:2025 - Structural Welding Code-Steel
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What is D1.1?
What is D1.1?
The code that defines how structural steel is welded, qualified, and inspected across buildings, bridges, and infrastructure.
D1.1/D1.1M:2025-AMD1 - Structural Welding Code–Steel, also called D1.1, is the premier welding code of the American Welding Society. Originally published in 1928 as the Code for Fusion Welding and Gas Cutting in Building Construction and called Code 1 Part A, D1.1 has evolved through multiple consolidations, redesignations, and revisions, and has since become the worldwide standard for welding structural steel.
Available in print and digital formats, D1.1 establishes requirements for welding structural steel and is routinely referenced in project contracts. It defines how welders and welding procedures are qualified, typical welding processes, and how welds are inspected and accepted.
What's New in D1.1:2025
The following updates reflect current practices and help reduce ambiguity in how the code is applied in the field. If you’re working from the 2020 edition, here’s where things have shifted.
Qualification Requirements
Updates and clarifications to procedure and welder qualification
Inspection Criteria
Refined acceptance criteria and inspection guidance
Materials
Updated material references and requirements
Organization
Reorganized sections for easier navigation and use
Technical Revisions
Added and revised content based on industry feedback
Why D1.1/D1.1M:2025 - Structural Welding Code-Steel Matters
Why D1.1/D1.1M:2025 - Structural Welding Code-Steel Matters
Trusted across the building and construction industries, D1.1 provides a shared framework for engineers, inspectors, and fabricators, outlining requirements that support consistent application of welding practices across projects.
Key use cases include:
- Defines qualification requirements for procedures and welders
- Establishes inspection and acceptance criteria
- Supports consistency across teams, shops, and job sites
- Referenced in contracts and project specifications
Who uses D1.1
D1.1 touches virtually every role involved in structural steel projects. From the shop floor to the executive offices, it provides a shared set of rules that guide how work is performed, inspected, and accepted—helping teams stay aligned and projects remain compliant.
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Engineers
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Fabricators
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Contractors
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Inspectors
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Educators
Engineers
reference D1.1 when designing joints, procedures, and materials, building projects that comply with industry standards from the ground up.
Fabricators
follow D1.1 to produce welds that consistently meet project specifications and pass inspections, keeping their work reliable and predictable.
Contractors
rely on it to coordinate teams, manage quality control, and fulfill contractual obligations without surprises.
Inspectors
use the code as the standard benchmark to evaluate weld quality and determine acceptability, ensuring every joint meets the required criteria.
Educators
and training programs teach welding procedures and qualifications based on the code, preparing the next generation of welders and inspectors for real-world applications.
Testimonial Block
I had been director of operations and worked with QC for 11 years when I decided to pursue a CWI. There’s a level of respect that comes with earning it, but understanding the D1.1 welding code at the CWI level elevates my expertise, vocabulary, and improves my ability to drive our quality control processes.
Frequently Asked Questions
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What is D1.1:2025?
D1.1:2025 is the American Welding Society’s Structural Welding Code—Steel. It establishes the requirements for welding structural steel, including procedure qualification, welder qualification, fabrication, inspection, and acceptance criteria..
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Who uses D1.1?
D1.1 is used by a wide range of welding professionals involved in structural steel work, including fabricators, inspectors, engineers, contractors, and educators. Each relies on the code to ensure all welding meets consistent technical and quality requirements.
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What types of projects use D1.1?
D1.1 is commonly applied to structural steel projects. It is intended for load-bearing steel applications rather than consumer products like appliances and often used by OEMs for designing and fabricating skids, modules, and equipment.
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Why is D1.1 important?
D1.1 provides the framework defining how structural steel welding is performed, qualified, inspected, and accepted. Because it is frequently referenced in contracts and project specifications, it plays a central role in quality assurance and safety.
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What does D1.1 cover?
The code includes requirements for:
- Welding procedure qualification
- Welder qualification
- Fabrication and workmanship
- Inspection methods
- Weld acceptance criteria
- Materials and design considerations
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What’s new in D1.1:2025 compared with D1.1:2020?
D1.1:2025 includes updates to qualification requirements, inspection criteria, material references, and technical clarifications.
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Is D1.1 required by law?
D1.1 itself is not automatically law, but it is often adopted into contracts, project specifications, and regulatory requirements, with AISC specifications referencing D1.1 for structural steel applications. When referenced in those documents, compliance with D1.1 becomes mandatory for that project.
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Does D1.1 apply to appliance manufacturing?
No. D1.1 is specifically written for structural steel welding and is intended for load-bearing steel applications. Appliance manufacturing generally falls under other welding standards depending on materials and product requirements..
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How do I know if I need D1.1:2025?
- Because your project specification or contract requires using D1.1.
- Your structural steel project requires qualification of welding procedures and welder performance or inspection of the welds.