CSWIP 3.1 vs AWS CWI: Which Welding Inspector Certification Should You Get?
CSWIP 3.1 or AWS CWI? Compare codes, units, eligibility, exams and renewal, and how to choose based on the projects and region you want to work in.
Written by Deepak RawtalReviewed by Nilanjan Sen
Published 19 Oct 2026Reviewed 7 Oct 20265 min read
Both say you are a qualified welding inspector, and both are recognised around the world. But they are built on different code families, tested in different units and renewed on different cycles. Choosing between them is less about which is "better" and more about which matches the codes on the projects you want to work on.
Short answer: CSWIP 3.1 trains and tests you to ISO and EN standards, in millimetres. AWS CWI tests you to AWS, ASME and API codes, in inches, including an open-book code exam. In the Gulf and India both appear in job adverts, so let the client specifications in your target market decide.
Two schemes, two code families
CSWIP is administered by TWI Certification Ltd in the UK. CSWIP 3.1 Welding Inspector is the middle rung of a three-step ladder: 3.0 Visual Welding Inspector, 3.1 Welding Inspector and 3.2 Senior Welding Inspector. The scheme rules are in TWI's document CSWIP-WI-6-92, whose 18th edition was published in July 2026.
CWI, the Certified Welding Inspector, is the American Welding Society's credential, governed by the AWS QC1 specification. It sits between the Certified Associate Welding Inspector (CAWI) and the Senior Certified Welding Inspector (SCWI).
Who can sit
| CSWIP 3.1 Welding Inspector | AWS CWI | |
|---|---|---|
| Experience routes | 3 years' welding inspection experience; or 2 years as a CSWIP 3.0 Visual Welding Inspector; or 1 year as a CSWIP Welding Instructor or Welding Foreman/Supervisor | From 1 year of welding-based work (with a relevant degree) up to 12 years (with less formal education), on AWS's education-and-experience table |
| Other checks | Experience must match the duties set out in the scheme document | Eye examination and application documents as set out by AWS |
| Where it is governed | TWI document CSWIP-WI-6-92 | AWS QC1 |
How the exams work
- CSWIP 3.1: candidates must attend a CSWIP-approved training course before the exam, unless they qualify for the scheme's mature-candidate route. The exam has two multiple-choice theory papers (80 questions in 2 hours, and 40 questions on welding procedures and welder certificates in 1 hour 30 minutes) and a practical in which you inspect and report on eight welded specimens (1 hour 30 minutes). You need 70% in every part, not just overall.
- AWS CWI: three parts. Part A, Fundamentals and Part C, Code Book are computer-based at more than 450 Prometric centres worldwide; Part C is open book on the code you select, such as AWS D1.1 or API 1104. Part B, Practical is hands-on, using equipment provided by AWS. You need 72% in each part.
The practical parts are where most candidates are tested hardest. CSWIP's practical puts real welds in front of you; CWI's Part B tests measurement and evaluation with AWS's kit. Practise with the actual gauges and on real specimens for either one.
Keeping it valid
- CSWIP: renew at the five-year point with a verified work record covering at least four of the five years, and recertify by examination at the ten-year point.
- AWS CWI: valid for nine years, with renewal applications at years three and six, then recertification at year nine under QC1's rules.
How to choose
CSWIP teaches you to think in ISO and EN terms: ISO 5817 quality levels, ISO 9606 welder qualification, ISO 2553 weld symbols, all in millimetres. CWI teaches you to think in AWS, ASME and API terms: AWS D1.1, API 1104, ASME Section IX and AWS A2.4 symbols, in inches.
In the Gulf and India, both credentials appear regularly, because projects follow the client's specification and the EPC contractor's procedures. The most reliable way to decide is simple: open 20 current job adverts for the roles you want, in the countries you want, and count which credential they name.
- Early in your career, aiming for Gulf EPC work: CSWIP 3.0 builds the basics and shortens the experience you need for 3.1 to two years. Check how often CWI appears in the adverts you collected.
- Working on pipelines built to API 1104 or structures to AWS D1.1: CWI is aligned with the codes you use every day.
- Offshore or European-specified work: CSWIP is usually the closer match.
Where API 577 fits
If you already hold API 510, 570 or 653, you qualify automatically for API 577 Welding Inspection and Metallurgy. It complements either welding inspector credential by adding the metallurgy and in-service repair view used in refinery and plant work. Read our API 577 guide for the details.
Preparing with EIM
EIM is an independent training provider; CSWIP belongs to TWI and CWI to AWS. EIM's self-paced preparation for CSWIP 3.0, 3.1 and 3.2 includes a question bank, practice mode with explanations, timed mock tests, study notes and flashcards, with one year of access. See the CSWIP exam pages
For practical defect knowledge, EIM's live Welding Repair and Inspection course is led by Mr. Deepak Rawtal, Senior Metallurgical Inspection Engineer with 45 years in metallurgical and materials testing. It covers welding quality and terminology, defects and their causes, radiographic interpretation, visual inspection and weld repair techniques, with case studies.
Next batch: 28 to 31 December 2026, Monday to Thursday, 19:00 to 21:00 UAE time.
4 sessions of 2 hours, with an EIM certificate of completion. See the course
Frequently asked questions
Is CSWIP 3.1 accepted in the Gulf?
CSWIP and CWI both appear in Gulf job adverts. What decides acceptance on a given project is the client's specification, so check the requirement for the work you are applying for.
Can I convert CSWIP to CWI, or the other way round?
There is no automatic conversion. Both bodies publish their own recognition and reciprocity rules, which change over time, so check TWI's and AWS's current documents before relying on one.
Which exam is harder?
They are hard in different ways. CSWIP requires 70% in every paper, including inspection of real specimens. CWI requires 72% in each of three parts, including an open-book code exam against the clock.
Do I need CSWIP 3.0 before 3.1?
No. Holding 3.0 shortens the experience you need for 3.1 from three years to two, as long as your duties match the scheme's requirements.
Does it matter that one uses millimetres and the other inches?
Yes, in practice. Your measuring habits, gauges and acceptance criteria will follow the units of the code you use. Practise in the units of your exam.
