The Elcometer 501 Pencil Hardness Tester (part number H501-1) determines the hardness of a coating using the pencil hardness method, also known as the Wolff-Wilborn test, which uses the graded hardness of graphite pencils to find the point at which a coating is marked. Coating hardness indicates how completely a film has cured; a coating that has not dried or cured properly can suffer poor adhesion, flaws and premature failure, so the pencil test gives a quick read on cure quality.

The Elcometer 501 Pencil Hardness Tester holds the prepared cylindrical pencil lead at a constant angle of 45 degrees and applies a fixed downward force of 7.5N, removing the operator variability inherent in free-hand testing and giving repeatable, comparable results. The pencil, sharpened and flattened on abrasive paper beforehand, is locked into the body of the Elcometer 501 Pencil Hardness Tester and pushed across the smooth, flat coated surface. The lowest pencil hardness that marks the coating defines its rating.

Supplied as a complete kit, the Elcometer 501 Pencil Hardness Tester includes a set of 14 pencils in grades 6B to 6H, a positioning block, two pencil sharpeners, an abrasive paper block, a carry case and operating instructions. The Elcometer 501 Pencil Hardness Tester measures 130 x 130 x 50mm with pencils, weighs 2.1kg, and an optional calibration certificate is available. The Elcometer 501 Pencil Hardness Tester can be used in accordance with ASTM D 3363, BS 3900-E19, EN 13523-4, ISO 15184, JIS K 5600-5-4 and ECCA T4. Used in coatings quality control across paint, coil and finishing industries, it is supplied by BAMR, South Africa's authorised Elcometer distributor.