Overview
EN ISO 16348:2003 - "Metallic and other inorganic coatings - Definitions and conventions concerning appearance" defines appearance-related terminology and sets out the principles for validating appearance when it is specified as a requirement for metallic and other inorganic coatings. Published by CEN in alignment with ISO 16348:2003, the standard helps ensure consistent visual assessment and agreement between suppliers, manufacturers and purchasers.
Key topics and requirements
- Definitions: Clear, standardized terms such as appearance, uniformity of appearance, blemish and visible defect to avoid ambiguity in specifications and inspection.
- Principle: When appearance is a contractual requirement, a validation test is mandatory - particularly for use as a referee method. A description alone is insufficient.
- Comparator / reference approach:
- Use of representative approved reference samples to define acceptable appearance and allowable variation.
- Reference samples should be produced with the same fabrication and coating processes as the finished parts to ensure reproducibility.
- All interested parties must agree on reference samples; samples should be retained for future reference and inspection.
- Note: special storage or expiry considerations may apply to preserve sample durability.
- Measurement techniques: Instrumental methods (e.g., glossmeters, surface profiling, colour matching) may be used where the product standard or purchase order specifies required properties.
- Inspection conditions: Lighting, viewing angle, magnification and distance must be agreed at enquiry/order time to ensure consistent inspection.
- Test report requirements: At minimum the report shall include:
- type of test/specification number
- test and examination conditions
- details of the article tested
- any deviations from the product standard
Applications and who uses this standard
EN ISO 16348:2003 is practical for:
- Coating suppliers and applicators defining acceptance criteria for metallic coatings
- Manufacturers and OEMs specifying visual quality requirements in purchase orders
- Quality managers and inspection labs performing appearance validation and referee testing
- Procurement and contract engineers seeking clear contractual definitions for appearance
- Test houses and certification bodies needing standardized reporting and inspection conditions
Typical uses: acceptance testing, quality control, dispute resolution (referee comparisons), and development of product standards specifying appearance.
Related standards
- EN ISO 2064:1996 - measurement of coating thickness
- ISO 2079 - general classification of surface treatment terms
- ISO 2080 - electroplating vocabulary
- ISO 10289 - corrosion test rating of coatings
- EN 12508 - vocabulary for corrosion protection and coatings
Keywords: EN ISO 16348:2003, metallic coatings, appearance validation, reference samples, coating uniformity, inspection conditions, comparator method.
