ASTM D3363 Film Hardness

Scope:

ASTM D3363 test is used for evaluating the film hardness of an organic coating on a substrate through the use of pencil leads or drawing leads. Also, the coating cure can be estimated by this test. ASTM D3363 test method can be used after an accelerated aging test to describe the development of the hardness of the substance over time. The ASTM D3363 test is similar to ISO 15184 in terms of content, but technically they do differ. 

Test Procedure:

A coated panel is set on a firm horizontal surface for ASTM D3363 testing. A pencil lead or drawing lead is carried firmly against the film at an angle of 45° and also pushed away from the operator machine in a 0.25 inches stroke. The procedure usually starts with the hardest pencil and the process is continued down the scale of hardness. The scale of hardness can be reported as two end-points – either the pencil that will not cut into or make a hole in the film known as pencil hardness or the pencil that will not abrade the film known as scratch hardness.

Sample size:

The samples used for the test will be as stated by ASTM D3363 guidelines. The coating film thickness should be stated or agreed upon both by the purchaser and the seller. 

Data:

Scale of hardness 

Relative humidity

Conclusion:

ASTM D3363 test is used for evaluating the film hardness of an organic coating on a substrate through the use of pencil leads or drawing leads.