Significance and Use 4.1 Coatings, to perform satisfactorily,
must adhere to the substrates on which they are applied. This
test method has been found useful as a simple means of assessing
the adhesion of coatings. Although this method is a qualitative
and a subjective test it has been used in industry for many
years and can provide valuable information. 4.2 Other adhesion
test methods may be useful in obtaining quantitative results.
See D2197, D3359, D4541, and D7234. 4.3 The Performance
Evaluation Scale (see 7.4, Table 1) is based on both the degree
of difficulty to remove the coating from the substrate and the
size of removed coating. TABLE 1 Rating System Coating is
extremely difficult to remove; fragments no larger than
approximately 0.8 by 0.8 mm (1/32 in. by 1/32 in.) removed with
great difficulty. Coating is difficult to remove; chips ranging
from approximately 1.6 by 1.6 mm (1/16 by 1/16 in.) to 3.2 by
3.2 mm (1/8 by 1/8 in.) can be removed with difficulty. Coating
is somewhat difficult to remove; ch