API 510 vs 570 vs 653 Exam Pass Rates: What API Publishes

API publishes historical exam performance for its Individual Certification Programs. This page summarises the per-window pass rates for API 510, 570 and 653 from the ICP status update dated April 2025, explains what the numbers can and cannot tell you, and links to the exam format and Body of Knowledge.

Per-Window Pass Rates Reported by API

CertificationPer-window pass rates reported by API (2020 – early 2025)
API 510About 54% to 69%
API 570About 45% to 70%
API 653About 62% to 76%

Source: API Individual Certification Programs status update, breakdown as of 30 April 2025 (historical exam performance tables). The pass point is a scaled score of 400. API does not break these figures down by first attempt, retake, region or preparation method.

How to Read the Numbers

  • Each figure is for one exam window and all candidates in it; first-time and repeat candidates are combined.
  • Rates move by several points between windows; compare ranges rather than single windows.
  • API 510 and 653 went through standard settings in November 2019 and API 570 in November 2020, and the March-May 2020 windows were disrupted by COVID-19, so earlier figures are not directly comparable.
  • No reliable public data splits pass rates by country, employer or preparation method. Claims of “first-time vs overall” or “self-study vs classroom” pass rates are estimates, not API data.

Exam Format (All Three)

  • 170 multiple-choice questions, 140 scored and 30 unscored pretest items
  • Closed-book part: 110 questions in 2.75 hours; open-book part: 60 questions in 3.75 hours with the references provided on screen; about 7.5 hours in total including a tutorial and a 45-minute break
  • In person at Prometric test centers only — API 510, 570 and 653 are not available by remote proctoring (remote delivery ended with the September 2024 window)
  • Scaled scoring; Prometric emails a score report, typically within 24 hours, and API uploads final results to the ICP portal afterwards

Common Reasons Candidates Fall Short

API does not publish failure analysis; the following is practical guidance. Candidates commonly run short of time in the open-book part, are slow on the calculations listed in the Body of Knowledge (corrosion rate, remaining life, intervals, MAWP and the construction-code thickness formulas), or study documents that are not on the effectivity sheet. API 579 (fitness-for-service) and API RP 580/581 (risk-based inspection) are not referenced publications for API 510, 570 or 653.

Which Exam Is Hardest?

On API's 2020–2025 figures, API 653 windows generally sat at or above API 510, with API 570 showing the widest spread. Difficulty for an individual depends mostly on familiarity with the construction code involved: ASME VIII for API 510, ASME B31.3 for API 570, and API 650 for API 653.

Frequently Asked Questions

Does API publish official pass rates?

Yes. API ICP status updates include historical exam-performance tables with candidates, passes, fails and pass percentages per window for each program.

What is the API 510 pass rate?

API's April 2025 status update shows per-window API 510 pass rates of roughly 54% to 69% between 2020 and early 2025.

What is the API 570 pass rate?

Roughly 45% to 70% per window between 2020 and early 2025, according to the same API status update.

What is the API 653 pass rate?

Roughly 62% to 76% per window between 2020 and early 2025, according to the same API status update.

What score do I need to pass?

API uses scaled scoring with a pass point of 400; it does not publish a percent-correct equivalent.

Does preparation method change the pass rate?

API does not publish pass rates by preparation method. Structured study of the referenced editions and timed practice are sensible, but specific uplift percentages quoted online are not API data.

Atlantis NDT does not offer API 510, API 570 or API 653 exam preparation. We provide ASNT SNT-TC-1A NDT training, ASNT Level III consulting and inspection software.

Atlantis NDT Products & Services

Passing is the gate; running an inspection program is the job. Atlantis NDT supports inspection teams end-to-end with NDT inspection management software — Atlantis ERP, our digital twin platform for asset integrity, and purpose-built NDT reporting software. Our NDT training & certification programs are authored by an ASNT NDT Level III, while ASNT Level III consulting and 3D laser scanning services cover the full inspection lifecycle. Everything is affordable, accessible, and fully customizable — book a free consultation for a tailored quote.

Running this as a programme, not a one-off

If you are responsible for an inspection programme rather than a single job, the recurring problem is rarely the code — it is keeping measured thickness, damage-mechanism assignment and next-inspection dates in one defensible place. Asset integrity management software covers keeping measured thickness readings per CML in one place, so the RBI (API 580/581) and fitness-for-service (API 579) work your integrity team or its specialists carry out starts from measured data rather than default rates. Atlantis supplies the NDT data and the software to hold it; it does not perform RBI or FFS assessments.

Practise before the exam

Written papers test what you know; employers and practical examinations test what you can do with a probe in your hand. Use the free practice tests to find your gaps, then practise the technique.