During Scratch Testing, a conical spherical tip, diamond or WC, is
drawn across the coated surface with an increasing load, resulting
in various types of failure at specific critical loads.

These critical loads are used to quantify the
adhesive and cohesive properties of different film/substrate
combinations. In addition, failure points can be determined using
frictional force and depth measurements.

Depth measurements provide the plastic and elastic portion of the deformation.

Constant road scratch testing can be used, in mapping, to check the surface uniformity.