DeFelsko PosiTest PT Manuel D'instructions page 6

Testing in Accordance with ASTM D3363
1. Starting with the hardest lead (6H), hold the pencil against the
coating at a 45° angle (point away from operator) and push the
pencil away from the operator for at least 6.5 mm (1/4 in). Sufficient
pressure should be used to either cut or scratch the coating, or
crumble the edge of the lead.
2. Repeat the test, moving down the hardness scale with each test,
until a pencil will not cut through the coating to the substrate (base
material or a previous coating) for a distance of at least 3mm
(1/8 in). This pencil is reported as the gouge hardness.
NOTE:
For improved accuracy, the PosiTest PT Pencil Hardness
Test Cart can be used to hold the pencil and exert constant pressure
while testing.
3. If required, continue to perform the test, moving down the hardness
scale with each test, until a pencil will not scratch or deface the
coating. This pencil is reported as the scratch hardness.
4. Perform the procedure detailed in Steps 1 – 3 twice.
G
G = Gouge Cut
G S
S = Scratch Cut
S M
M = Pencil Mark only
Top Coat
Substrate or
Base Coat