The pencil hardness test, also referred to as the Wolff-Wilborn test, uses the varying hardness values of graphite pencils to evaluate a coating’s hardness.

The Test Block is so designed to ensure that the cylindrical pencil lead is maintained at a constant angle of 45° and exerts a force of 7.5N approx.

The pencil lead, prepared beforehand using the special sharpener and abrasive paper, is provided with the instrument and pushed over the smooth, flat coated surface.

The lowest hardness value of the pencil which marks the coating determines the coating’s hardness rating.

The instrument is supplied complete with set of hardness pencils (12/14/17/19 pencils),
positioning block, x1 pencil sharpener, abrasive paper set, carry case and operating instructions

can be used in accordance with

Optional Accessories / spares

• ‘Mitsubishi’ Japan make pencil set of 12 pencils (customize set)
• ‘Mitsubishi’ Japan make pencil set of 17 pencils

• 12 Pencils Set (STAEDTLER German make Pencils) 6B to 4H
• 19 Pencils Set (STAEDTLER German make Pencils) 8B to 6H
• Graphite pencil Sharpner
• Positioning Block
• Abrasive Paper Set.