• ISO Class.: 4 / ASTM Class.: 1 B
The coating has flaked along the edges of the cuts in large ribbons and/or some squares have detached partly or wholly. A cross-cut area significantly greater than 35 %, but not significantly greater than 65 %, is affected.

The cross-cut test is a simple and easily practicable method for evaluating the adhesion of single- or multi-coat systems.

Procedure

– Make a lattice pattern in the film with the appropriate tool, cutting to the substrate
– Brush in diagonal direction 5 times each, using a brush pen or tape over the cut and remove with Permacel tape
– Examine the grid area using an illuminated magnifier

Cross-Cut Results

Adhesion is rated in accordance with the scale below.

• ISO Class.: 0 / ASTM Class.: 5 BThe edges of the cuts are completely smooth; none of the squares of the lattice is detached.

• ISO Class.: 1 / ASTM Class.: 4 B
Detachment of small flakes of the coating at the intersections of the cuts. A cross-cut area not significantly greater than 5 % is affected.

• ISO Class.: 2 / ASTM Class.: 3 B
The coating has flaked along the edges and/or at the intersections of the cuts. A cross-cut area significantly greater than 5 %, but not significantly greater than 15 %, is affected.

• ISO Class.: 3 / ASTM Class.: 2 B
The coating has flaked along the edges of the cuts partly or wholly in large ribbons, and/or it has flaked partly or wholly on different parts of the squares. A cross-cut area significantly greater than 15 %, but not significantly greater than 35 %, is affected.