Welding certifications explained: AWS, ASME, and the D-codes
What counts as a welding certification?
Three different things get called "welding certification," and they work differently. AWS issues two personal credentials directly to individual welders: Certified Welder (CW) and Certified Welding Inspector (CWI). The D-series codes (D1.1, D1.2, D1.3, D1.5, D1.6, D1.8) are qualifications an employer tests a welder against, not certifications AWS grants to a person. ASME welding qualifications work the same way: the employer, not ASME, issues them, under the employer's own ASME-accepted quality program. Knowing which category a credential falls into changes who administers the test and who you would contact to verify it.
AWS Certified Welder (CW)
AWS Certified Welder is a performance-only test: there is no required course to sit for it, and no prerequisites. A welder demonstrates skill directly on the test itself. CW runs on a six-month recertification cycle, shorter than most professional credentials, which keeps the certification tied to a welder's current, demonstrated ability rather than a one-time pass.
AWS Certified Welding Inspector (CWI)
AWS Certified Welding Inspector is a separate, career-advancement credential, distinct from CW. Where CW certifies welding performance, CWI certifies inspection knowledge, requiring documented experience and a passing score on AWS's exam. The exact prerequisite structure varies by applicant background; confirm current requirements directly with AWS before planning around a specific timeline.
The D-series codes: employer-tested, not AWS-certified
The D-series codes are what employers actually cite in job postings, and they work differently from CW and CWI. Each code covers a specific application, and a welder qualifies to one by passing an employer-administered test that follows that code's procedure, not by receiving a certification AWS issues to the individual:
- D1.1: structural steel
- D1.2: aluminum
- D1.3: sheet steel
- D1.5: bridge welding
- D1.6: stainless steel
- D1.8: seismic supplement, applied alongside D1.1 on seismic-resistant structures
A welder can hold a CW certification and still need separate qualification to any of these codes, since they measure different things. CW measures general performance, and a D-series qualification measures competence to a specific code's procedure and position requirements.
ASME qualifications: issued by the employer, not by ASME
ASME welding qualifications are issued by the employer, under the employer's own ASME-accepted quality program, not by ASME directly to an individual welder. There is no ASME-certified-welder registry to check a name against, and no personal ASME credential that travels with a welder the way AWS CW does. People used to a national body handing certifications to individuals often assume ASME works the same way. It does not: the qualifying authority is the employer's program.
Is there a state welding license?
No general state license exists for welders. State regulation is concentrated specifically in boiler and pressure-vessel work, in Massachusetts, Ohio, and Wisconsin, plus city-level rules in New York City and Chicago, loosely coordinated through the National Board of Boiler and Pressure Vessel Inspectors. Outside boiler and pressure-vessel work, welding is not a state-licensed trade the way electrical work often is. This is informational, not legal advice: confirm current requirements with your state board before assuming any rule applies, or doesn't apply, to your situation.
Why the distinction matters when you're job hunting
A job posting that asks for "ASME certification" is describing a qualification you would earn under a specific employer's program, not a credential you can walk in already holding from a prior employer, since ASME qualifications do not transfer between employers the way an AWS CW certification does. The same logic applies to the D-series codes: a D1.1 qualification earned under one employer's testing does not automatically carry to a new employer, since the new employer typically administers its own test. AWS CW and CWI are the two credentials in this list that belong to the individual welder rather than to an employer's program, which is why they are the ones a welder can point to independent of who they currently work for.
How these pieces fit together
A welder building a credential record typically starts with AWS CW to establish baseline, documented performance, then adds employer-tested D-series or ASME qualifications specific to the work being pursued, and may later pursue CWI as a separate inspection-track credential. None of these substitute for each other, and none functions as a general license. The certification codex covers all eight credentials and codes referenced here in full detail.
FAQ
What's the difference between AWS CW and the D-series codes?
CW is a personal certification AWS issues after a performance-only test. The D-series codes (D1.1, D1.2, D1.3, D1.5, D1.6, D1.8) are qualifications an employer tests a welder against for a specific application; AWS doesn't issue them to individuals the way it issues CW.
Does ASME certify individual welders?
No. ASME welding qualifications are issued by the employer under the employer's own ASME-accepted program. No ASME-certified-welder registry exists.
Is there a national or state welding license?
No general welder license exists at the state or national level. Regulation is concentrated in boiler and pressure-vessel work in Massachusetts, Ohio, and Wisconsin, plus New York City and Chicago. Confirm current rules with your state board.
How often does AWS CW need to be renewed?
Every six months, per AWS's published recertification cycle for the Certified Welder credential.