The cleaning level of metal surface treatment is also the cleanliness. The standards are: SSPC- and Sa-, these two. Now let's talk about Sa-, the standard. Sa-, divided into four grades are Sa1, Sa2, Sa2.5, Sa3. Please see the details below.

Sa1 level

The general simple manual brushing and abrasive cloth grinding methods are used, which is the lowest level of the four cleanliness, and the protection of the coating is only slightly better than that of the untreated workpiece.

According to the technical standard, the surface of the workpiece should be free of oil, grease, residual oxide scale, rust, and residual paint.

Sa2 level

The sandblasting cleaning method is adopted, which is the lowest level in sandblasting treatment, that is, the general requirement, but the protection of the coating is much higher than that of manual brushing and cleaning.

Technical standards, the surface of the workpiece should be free of greasy, dirt, scale, rust, paint, oxides, corrosion, and other foreign substances, but the defects are limited to no more than 33% of the surface per square meter, which may include slight shadows.

Sa2.5

It is widely used in the industry and can be used as the level of acceptance technical requirements and standards.

The technical standard is the same as the first half of the Sa2 requirements, but the defects are limited to no more than 5% of the surface per square meter, which may include slight shadows. A small amount of slight discoloration caused by defects and rust; oxide scale and paint defects.

Sa3 level

The grade is equivalent to the American SSPC-SP5 grade, which is the highest surface treatment grade in the industry, also known as the white cleaning grade.

The technical standard is the same as the Sa2.5 level, but 5% of shadows, defects, rust, etc. have to exist.

The above points are the cleaning grade standards for metal surface treatment. Different levels have different requirements.