ASTM D 3363 - 05 (Reapproved 2011). Standard Test Method for Film Hardness by Pencil Test

American Society for Testing and Materials (ASTM). Current edition approved June 1, 2011. Published June 2011. Originally
approved in 1974. Last previous edition approved in 2005 as D3363 – 05. 3 p.
NOTES: Figure 1 was corrected editorially in August 2011. Figure 2 and Section 7 were corrected editorially in March 2012.
This test method covers a procedure for rapid, inexpensive determination of the film hardness of an organic coating on a substrate in terms of drawing leads or pencil leads of known hardness.
Summary of Test Method:
A coated panel is placed on a firm horizontal surface. The pencil is held firmly against the film at a 45° angle (point away from the operator) and pushed away from the operator in a 6.5-mm (1⁄4-in.) stroke. The process is started with the hardest pencil and continued down the scale of hardness to either of two end points: one, the pencil that will not cut into or gouge the film (pencil hardness), or two, the pencil that will not scratch the film (scratch hardness).