This instrument has been designed for the measurement of the hardness of protective coatings. The degree of hardness of paint films, plastic coatings, etc. can be accurately measured and recorded with the Hardness Test Pencil. No matter whether on a level or curved surface, small or large. The instrument is always ready for use and, because of its small size easy transportable, an asset which will be appreciated by all concerned with hardness tests.

The handling of the Hardness Test Pencil is extremely simple. The estimated or known spring tension is set with the help of the slider. Holding the instrument upright and placing its point on the test surface one draws a 5 to 10 mm long line at a rate of approximately 10 mm/sec. The stylus should produce a scratch which is just visible with the naked eye. If the spring pressure is too high, the scratch is clearly visible; if too low, no scratch appears. The applied pressure, fixed by locking the slider, is marked in Newton’s.

Three scales are engraved into the test pencil for the three pressure ranges:

No.1：0 – 3 N (blue marked)

No.2：0 – 10 N (red marked)

No.3：0 – 20 N (yellow marked).