Pencil Hardness Test Hb

A pencil hardness test is a type of evaluation method that is performed to determine the hardness of a material typically coating materials. Elcometer 501 pencil hardness tester the pencil hardness test also referred to as the wolff wilborn test uses the varying hardness values of graphite pencils to evaluate a coatings hardness. Using this scale the hardness of the core is often marked on the pencil look for a number such as 2 2 12 or 3.

Top Pencil Hardness Test Hb, Hardness symboled with h scales.

Pencil hardness test hb. The pencil hardness test also referred to as the wolff wilborn test uses the varying hardness values of graphite pencils to evaluate a coatings hardness. The samsonic pencil hardness tester is used for verifying the hardness values of graphite pencils to evaluate coating hardness. The elcometer 501 pencil hardness tester has been designed to ensure that the cylindrical pencil lead is maintained at a constant angle of 450 and exerts a force of 75n 168lbf. January 27 2018 pencil hardness mohs scale astm d3363 9h 10h explanation post about h hardness scales mohs scale pencil hardness standards astm d3363 iso 15184 pencil hardness test pencils 9h10h.

This test defines a pencil hardness of a coating as the grade of the hardest pencil that does not permanently mark the coating when pressed firmly against it at a 45 degree angle. Mohs a mineral stones hardness scale. The pencil hardness test by mac simmons. The first graphite grading scale is a numeric scale.

Pencil hardness test graded pencils can be used for a rapid test that provides relative ratings for a series of coated panels but cant be used to compare the pencil hardness of different coatings. How to measure coating hardness using the wolff wilborn pencil hardness test duration. After doing some testing on various coatings for their pencil hardness i was surprised at the results i got. Eventually a pencil with hardness 5h is used but leaves a very slight mark on the surface.

A pencil with hardness hb is pressed onto the surface on a 45 degree angle but even though the pencil breaks it does not mark the surface. The test is repeated with increasingly harder pencils. The 5h pencil is the first one to permanently damage the. There are two graphite grading scales used to measure the hardness of a pencils graphite core.

The elcometer 501 pencil hardness tester has been designed to ensure that the cylindrical pencil lead is maintained at a constant angle of 450 and exerts a force of 75n 168lbf. This article appeared in woodwork april 2000 p76. Proper disclosure i own a ceramic coating factory research lab for over 2 years. The test block is so designed to ensure that the cylindrical pencil lead is maintained at a constant angle of 450 and exerts a force of 75n approx.

A set of graded pencils. To perform a pencil hardness test graphite pencils of varying hardness are moved across a coatings surface. And is used here by permission. Elcometer inspection equipment coatings industry 7290 views 831.