Test Background
Pencil hardness refers to the resistance of the paint film surface to scratches or other defects when a pencil with a prescribed size, shape and hardness pencil lead is pushed across the paint film surface. Paint and varnish film hardness tests can be carried out by pressing a pencil with a known hardness mark on the paint film. The test can be carried out on a single coat of paint, varnish and related products, or on the top layer of a multi-coat system.
Zhongke Testing Reliability Experiment Center has the capability of reliability testing of various paints and varnishes, and provides professional paint film hardness testing services for paints and varnishes.
Scope of tests
Color paint is divided into primer and topcoat: primer is divided into primer, putty, mid-coat, sealer, anti-rust paint, etc.; topcoat is divided into enamel paint, special topcoat, etc.
The paint and film of varnish are transparent and are divided into ester varnish, shellac varnish, phenolic varnish, alkyd varnish, acrylic varnish, polyester varnish, high-performance varnish, fluorocarbon varnish, etc.
Test method
The product or system to be tested is applied at a uniform thickness to a flat plate with a uniform surface structure. After the paint film has dried/cured, place the sample in a horizontal position and determine the pencil hardness of the paint film by pushing a pencil of increasing hardness across the film.
During the test, the pencil is fixed so that the pencil can press down on the paint film surface at an angle of 45° under a load of 750g. Gradually increase the hardness of the pencil until defined imperfections appear on the surface of the paint film.
Test standard:
GB/T 6739-2022 Paints and varnishes - Pencil method for determination of paint film hardness
ISO 15184: 2020 Paints and varnishes - Determination of paint film hardness by pencil method
BS EN ISO 15184-2012 Paints and varnishes - Determination of film hardness by pencil test
KS M ISO 15184-2013 Pigments and varnishes Determination of film hardness using pencil test
DIN EN ISO 15184-2013 Paints and varnishes Pencil test for determination of film hardness
EN ISO 15184-2012 Paints and varnishes – Determination of film hardness by pencil test
