Page 120 - 20250602 EEA QM Edition 6.0

Quality Requirements Edition 6.0 European Enamel Association

Testing report 8.6.3 Testing of adherence of porcelain and vitreous enamel to steel of more
than 3 mm thickness
In the testing report, the following has to be mentioned:

kind and origin of the test plates Purpose and scope
place and date of testing
The test method described in this specification sheet is to classify the adherence of
resistance class, according to EN ISO 28706-4 (classes AA-unclassified)
enamel to steel on enamelled articles made of steel heavier than 3 mm of thickness.
testing-time and -temperature

Test method
The enamelling of the test piece is to destroy by impact. The destruction can be
executed by a dynamic ball-indentation or a blow of a hammer. Because of the chipping
and splintering enamel safety glasses are absolutely to be worn during this test.

Test device
No binding regulation

Judgement of the test-spot

Following the destruction by only one single impact, relics of enamel on the steel
surface must be clearly visible. The steel surface may not appear silvery bright.
Because of the undefined mechanical shock method, a classification into ranks of
adherence is not possible. One virtually has to decide between “good” or “insufficient”.

Test report

To be mentioned in the test report:
kind and origin of the test piece
place and date of testing
location of the test-spot on the test piece
judgement of adherence / bond

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