Free 10-item check · no signup
API 510 exam prep: free practice check
Prepare for the API 510 exam with a free 10-item check. See your score by published Body of Knowledge domain and use it to choose your next study topic.
- 10 questions, untimed
- Answers explained as you go
- Scored by domain
Full API 510 course: $199, available now. See what's inside →
Exam at a glance
- Format
- 170 questions in 390 minutesBook: Closed-book part + open-book part; only the sections listed on the Publications Effectivity Sheet are available during the open-book part. Calculator, scratch paper and pencil provided; own papers and reference books not allowed
- Delivery
- Prometric computer-based test, in person at designated test centers only (API 510 is not available for remote testing)
- Fee
- Initial: 2026 $875 member / $1,125 non-member; 2027 $890 / $1,140. Late application $200. Reschedule (new window) $350
- Retakes
- No published attempt limit or waiting period. Each application is valid 6 months from the first requested exam date; after it expires a new application and full fee are required. API does not disclose failed exam contents
What it covers
Diagnostic questions follow these domains, subject to the available practice questions.
Original practice questions written to the published content outline. Never real or recalled exam questions.
How it works
Answer
10 questions, untimed. Check each answer to see why it's right, with a hint where one helps.
See your score
Blueprint-weighted, broken down by domain, with your weakest one named.
Study smarter
Add your email and exam date for a study plan. Ready for exam pace? The 25-question timed practice test pauses and saves your place.
The API 510 course
Available now · instant accessLearn every Body of Knowledge section, work the calculations step by step, then prove it on timed exams.
- 8modules of lessonsEvery task on the outline
- 2full-length timed exams170 questions in 390 minutes each
- 401practice questionsEach one explained
- 6worked calculationsStep by step
- 1week-by-week study planSet to your exam date
See all 8 modules
- API 510: scope, the inspector, repairs and rerating
- Corrosion rates, remaining life and inspection intervals
- Required thickness and MAWP under Section VIII Division 1
- Pressure testing and impact test exemptions
- Welding procedures, qualifications and welding practice
- Nondestructive examination
- Damage mechanisms, materials and vessel inspection practice
- Relief devices, material verification and repair methods
Question bank and timed exams · Expert review in progress: questions marked Reviewed were checked by a pressure vessel inspection professional with 13 years in the industry (Oct 19, 2026). The newest questions are still being reviewed. Every answer key is confirmed by a separate blind solve, and reported errors are fixed within 2 business days.
The Long Seam app
Study for the API 510 anywhere you are
We're building Long Seam for iPhone and Android, so your practice questions, study plan and timed exams are always one tap away.
- Today's questions, aimed at your weakest domain
- Your week's plan, counting down to exam day
- The same original questions and explanations as the site
Early designs of the Long Seam app. Until it's out, everything here works in your phone's browser.
API 510 exam prep FAQ
How long is the free diagnostic?
The free check has 10 practice items, is untimed and takes about 23 minutes. You see the answer and explanation after each item. It is a short study check, rather than a full-length exam simulation. Want exam pace? The 25-item timed practice test is also free. You can pause it, and it saves your place.
What does this API 510 exam diagnostic cover?
The diagnostic groups practice by the API 510 Body of Knowledge for pressure vessel inspector preparation. It is a short study check, not a full exam simulation. Use the Body of Knowledge and Publications Effectivity Sheet for your exam window when choosing references.
Is the diagnostic free?
Yes. You can start the diagnostic and see your score and domain breakdown for free, with no signup or payment.
Where does the practice content come from?
These are original practice questions written to the published outline. We never use real or recalled exam items. Treat the results as a starting point for study.
How is the diagnostic scored?
Practice items are grouped by the published outline's domains, subject to available questions. The outline does not publish domain percentages, so the diagnostic uses equal domain weights; these are practice weights, not published exam weights. This practice percentage helps set study priorities; it does not predict your exam score or certification outcome.
What do I see after finishing?
You see your overall practice score, a domain breakdown and your weakest domain. Use those results alongside the published outline to choose topics to revisit.
How should I use the result to study?
Review the domains where you struggled, compare them with the published outline and return to your study references. A short diagnostic samples only part of the content; completing it does not establish exam readiness.
- 01Free API 510 check10 questions, untimed, about 23 minutes. Answers explained as you go.Start free
- 02Free sample lessonCorrosion rates, remaining life and inspection intervals: a full lesson from the course.Read the sample
- 03API 510 course$199. Lessons, timed practice exams and a plan around your exam date.See the plans
Want the full picture first?Format, domains, references and published sources in one page.
Read the API 510 exam guide