ASTM D3363 Tests

ASMT D3363 is a test method designed to evaluate the hardness of a coating using pencil or drawing tips. Curing of the coating can also be evaluated by this standard. Finally, this test protocol can be used after an accelerated aging test to characterize the evolution of the material's hardness over time. For example, ASTM D155, based on ASTM G7869 implementation, is an example of a method that can be matched with ASTM D3363. As part of its paint testing services, EUROLAB performs ASTM D3363 tests as accredited.

Evaluation of film hardness with a pencil hardness test;

ASTM D3363 pencil test

The purpose of this test protocol is to determine the hardness of a coated film using pencil hardness measurements. This method consists of evaluating the surface aesthetics of the coating after applying a constant force and trying to draw it at an angle of 45o with a pencil of known hardness. This process is repeated with a pencil lower on the hardness scale until the two extremes are reached. The first is the hardest pencil that will leave the film uncut, and the second is the pencil that will not scratch the sample. Finally,

The main factors to consider when performing this test are film thickness and pen type.
It can make scratch hardness measurements according to ASTM D 3363. It uses pencil tips of constant pressure and varying hardness. Bits of varying degrees of hardness are moved over the tested surface under constant pressure and at a fixed angle to the surface. The degree of hardness of the pencil tip that damages the surface is taken as a measure of scratch hardness.

The instrument consists of a pencil holder carried on two cylinders whose weight is arranged so that the pressure exerted by the flat pencil tip is approximately 300 grams. A handle is provided to push the instrument over the sample. Fourteen pencils in grades 6B to 6H are used. Pen tips can be easily changed.