Which of the following refers to the thorough hand and power tool cleaning level considered in the inspection process?

The thorough hand and power tool cleaning level referred to in the inspection process is represented by the ISO St 3 standard. This standard describes the surface preparation level that involves the use of hand and power tools to remove all visible rust, mill scale, and other foreign matter, resulting in a clean surface with a defined texture. This level of cleaning is critical because it ensures proper adhesion of subsequent coatings and ultimately contributes to the longevity and performance of the coating system.

In contrast to the ISO St 3 standard, the other options represent different levels of cleaning. For example, ISO St 2 involves the removal of visible rust and mill scale but does not require the surface to be as clean and textured as in ISO St 3. Similarly, SSPC-SP1 is specific to solvent cleaning, and SSPC-SP3 refers to power tool cleaning that may not achieve the same level of cleanliness as ISO St 3.

Understanding these standards is essential for inspectors, as they define the expectations for surface preparation, which is a foundational step in ensuring that coatings perform as intended.