When a structural project specification says "inspection shall be performed by a qualified welding inspector," that phrase does real work. On an IBC-governed building or AISC-certified fabrication project, the qualification standard behind that language is almost always AWS QC1 — the American Welding Society's certification scheme that defines three distinct credential tiers: CAWI, CWI, and SCWI.
Understanding what each tier actually authorizes, what limitations it carries, and what AWS D1.1:2025 itself says about inspector qualification will help fabricators, contractors, and QC managers assign inspectors correctly and avoid the compliance gaps that get flagged in third-party audits and special inspection records.
The Three-Tier AWS Inspector Certification Structure
AWS QC1 establishes the framework for all three credentials. Each builds on the previous.
CAWI — Certified Associate Welding Inspector
The CAWI is an entry-level credential for individuals who are building experience in welding inspection but have not yet qualified for the full CWI examination. CAWIs must pass the AWS QC1 examination, but the experience requirements are lower, and critically, the authorization is limited.
A CAWI cannot make independent accept/reject decisions on production welds. CAWI work must be performed under the direct supervision of a CWI or SCWI, with the supervising inspector responsible for final disposition of any inspection result. The CAWI can conduct visual examinations, perform dimensional checks, witness preheat verification, and document findings — but a CWI must review and sign off.
For most structural steel fabrication projects, a CAWI alone does not satisfy the inspection requirement. A CAWI working directly with a supervising CWI on-site can fulfill inspection roles within that supervised scope, but the project cannot use a CAWI as the sole responsible inspector of record.
CWI — Certified Welding Inspector
The CWI is the baseline credential for independent structural weld inspection. It requires passing a three-part examination covering fundamentals, code book application, and a practical portion (visual acuity and weld discontinuity identification). Experience requirements are more stringent than for the CAWI, and candidates must demonstrate code familiarity across multiple AWS documents.
A CWI can:
- Make independent accept/reject decisions on welds
- Review and accept WPS and PQR documentation
- Conduct pre-weld, in-process, and final visual inspections
- Witness mechanical testing
- Sign inspection reports and acceptance records
- Supervise CAWIs
For the vast majority of AWS D1.1:2025 structural welding projects, the CWI satisfies the inspector qualification requirement. IBC Chapter 17 special inspection for structural steel welding specifically references a "certified welding inspector" — meaning the CWI credential.
SCWI — Senior Certified Welding Inspector
The SCWI is the highest tier under AWS QC1. Candidates must hold an active CWI credential, demonstrate additional years of experience, and pass a more comprehensive examination covering welding symbols, advanced code application, and inspection program management.
The SCWI is not simply a more experienced CWI — the credential represents a different scope of authorization. SCWIs are often required when:
- An inspection program involves supervising multiple CWIs and CAWIs across a large project
- The project specification or contract requires SCWI-level review of WPS submittals or audit documentation
- A fabricator's internal QC program structure requires SCWI sign-off on the overall welding quality program, not just individual weld inspections
Some owner specifications and AISC fabrication certification audits require an SCWI in a QC oversight role, while CWIs handle field inspection. This is common on larger infrastructure and industrial projects where the inspection workload requires a team structure.
What AWS D1.1:2025 Actually Requires
AWS D1.1:2025 addresses inspection qualification directly. The code requires that welding inspection be performed by "inspectors who have been qualified" — and then references the inspector's qualifications in terms that align with the AWS QC1 structure without mandating a specific credential by name.
In practice, the code's inspector qualification requirements are typically met through one of two paths:
- AWS QC1 certification — CWI (for independent inspection) or SCWI (for program oversight). The CAWI path requires the direct supervision structure described above.
- Engineering judgment or owner-specified alternative — Some owner specifications allow an individual who has demonstrated equivalent experience and code knowledge through documented evaluation. This is less common on publicly bid structural projects but does appear in industrial and process-plant work.
The structural engineer of record (EOR) or owner specification will usually be more prescriptive than D1.1 itself. On IBC-governed building construction, the special inspection requirements of Chapter 17 effectively mandate CWI credentials for the special inspector performing structural weld inspection.
Scope of Inspection Authority Under AWS D1.1
The code distinguishes between Contractor Quality Control (CQC) inspection — the fabricator's own inspector — and Owner's Verification Inspection (OVI). Both can be CWIs; the distinction is organizational, not credential-based.
CQC inspectors work for the fabricator and are responsible for ensuring every weld meets D1.1 and the contract specification before it leaves the shop or is accepted as complete in the field. Verification inspectors work for the owner (or owner's representative) and confirm CQC findings through surveillance and hold-point inspections.
Neither role changes the required credential: both positions require a CWI (or SCWI in program oversight roles) for independent accept/reject authority.
A CAWI assigned to the CQC function is not compliant with D1.1's inspector qualification intent unless a CWI is actively supervising that work on-site. Placing a CAWI on a night shift with no CWI available and signing off morning reports is a common compliance gap — and one that third-party auditors catch.
Common Compliance Mistakes
Using CAWI certifications to meet CWI requirements on staffing matrices. Some fabricators list both CWIs and CAWIs on their quality plan's "inspection personnel" roster in a way that implies equivalent authorization. Auditors reviewing the documentation will ask whether the CAWI operated independently.
Allowing lapsed credentials. CWI credentials must be renewed on a three-year cycle. Lapsed CWIs are not current, and their accept/reject decisions during the lapse period may be challenged in audits or disputes. QC managers should track renewal dates and pull any lapsed credential holder from inspection authority until renewal is confirmed.
Not specifying SCWI when the program requires it. Large multi-trade projects or fabricators seeking AISC Advanced Certification may need an SCWI designated as the Quality Control Manager (QCM), not just a CWI. Confusing the two in the quality manual can be a finding in AISC audits.
Expecting the EOR to care about the credential name. Most EORs do care — they are responsible for accepting the inspection records and signatory authority of the inspector. An inspector whose credential doesn't match the specification is a paperwork problem at final closeout, not just an abstract compliance issue.
Applying This to Your QC Program
A practical setup for a structural fab shop under AWS D1.1:2025:
- Designate at least one active CWI as the responsible QC inspector for production welding accept/reject decisions
- If CAWIs are part of the team, document the supervision structure in the quality plan and ensure a CWI is physically available to review findings before final disposition
- Check whether your project specification or the owner's requirements reference SCWI in any role — particularly for audit trail sign-off or WPS review authority
- Verify renewal dates for all credentialed personnel before project mobilization
The CWI is the workhorse credential for AWS D1.1 structural work. Understanding where it ends and where SCWI or supervised CAWI roles begin keeps inspection records defensible and audits clean.
Related reading: CWI pre-weld inspection requirements before first arc, inspector authority and organizational roles under AWS D1.1, and CWI inspection report documentation practices. For WPS and PQR tools built for CWI-led programs, see wpswelding.com pricing.