DeFelsko PosiTest PT Manuel D'instructions page 3

1. Prepare the pencil using the included sharpener. Sharpen the pencil
until ~5-6 mm (3/16 to ¼") of undisturbed, unmarked lead remains
above the wood.
NOTE:
The Pencil Sharpener included in the PosiTest PT Pencil
Hardness Test Kit incorporates two sharpeners, one sharpener is
used for pencils with hardness 6B– 3B, and the other sharpener is
used for pencils with hardness 2B – 6H.
2. Hold the pencil at a 90° angle and, using the supplied 400 grit
abrasive paper, rub the lead against the sandpaper until a flat,
smooth, and circular cross-section is obtained, free of chips or
nicks.
X X
5 – 6 mm