TECHNICAL STANDARD
SSPC-SP 7 / NACE No. 4
Brush-Off Blast Cleaning
AMPP / SSPC / NACE
2006
Current
WHAT DOES THIS STANDARD COVER?
Defines the brush-off degree of abrasive blast cleaning of steel surfaces before application of protective coatings or linings.
WHY IS IT RELEVANT?
Relevant where a relatively light abrasive blast-cleaning treatment is specified, including certain maintenance and overcoating applications. Do not confuse SP 7 for carbon steel with SP 16, which addresses brush-off blast cleaning of substrates including galvanized steel, stainless steel and non-ferrous metals.
KEY INSPECTION CONSIDERATIONS
The standard addresses brush-off blast cleaning of steel surfaces. The process removes specified loose material and contaminants while tightly adherent material may remain. The resulting surface condition is substantially different from commercial, near-white or white metal blast cleaning. Inspection should assess the actual prepared condition.
WHAT THE STANDARD SHOULD NOT BE USED TO ASSUME
Brush-off blast cleaning should not be treated as equivalent to higher degrees of blast cleaning such as commercial, near-white or white metal preparation. Tightly adherent coating, rust or mill scale may remain where permitted by the applicable requirement. The preparation grade does not independently establish surface profile or absence of soluble contamination. It should also not be confused with SSPC-SP 16, which addresses different substrate types.
PRACTICAL INSPECTION APPLICATION
The standard can be relevant to maintenance coating work where complete removal of existing tightly adherent material is not required. Inspectors can assess removal of loose and detrimental material, retained coating and transitions between prepared and existing surfaces. Surface profile, contamination and other specified tests should be assessed separately.
RELATED TECHNICAL STANDARDS
RELATED TECHNICAL TOPICS
Abrasive blast cleaning; Surface preparation; Carbon steel
RELATED PIL GUIDANCE
Practical guidance on assessing abrasive blast-cleaned steel surface profile before protective coating application.
A structured approach to investigating protective coating failure through evidence, testing, sampling and project-record review.
RELATED EXPERTISE
Coating Inspection; Technical Consultancy
ABOUT THIS TECHNICAL SUMMARY
Paint Inspection Ltd provides this information to help inspectors, engineers, asset owners and contractors understand the practical relevance of commonly referenced protective coatings standards. This page is PIL technical guidance and does not reproduce or replace the published standard. Users should refer to the current published standard, project specification, coating manufacturer requirements and other applicable contract documents when establishing project requirements or acceptance criteria.
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OFFICIAL STANDARD
PIL technical summaries are intended to explain the inspection relevance of industry standards and do not replace the published document.
STATUS AND SOURCE VERIFICATION
Current published joint surface-preparation standard identified as SSPC-SP 7-2006 / NACE No. 4. Verified September 2026.