Pencil Hardness Testing

The Wolff-Wilborn test, also known as the pencil hardness test, uses multiple graphite pencils, each with varying degrees of hardness, to assess the coating’s hardness. Each pencil is dragged across the surface to evaluate the coating’s hardness or resistance to abrasions and scratches. The softest pencil that can scratch the surface determines the coating’s hardness.

Why is Coating Hardness Important?

Hard coatings generally provide greater resistance to scratching and abrasion, while softer coatings may be prone to premature failure. Manufacturers rely on hardness testing to determine the qualities of their coatings which helps determine their best uses. Some environments and applications are too harsh for some coatings, so conducting hardness testing is essential to ensure the coating hardness is appropriate for the desired application.

ASTM D3363

ASTM D3363 is the standard method for pencil hardness testing. The test method evaluates coating hardness on a spectrum ranging from B (soft) to HB (medium) and H (hard). Pencil hardness tests have several advantages, including:

About Applied Technical Services

Since our founding in 1967, ATS has provided consulting engineering, inspection, and testing services to clients in various industries worldwide, including:

We employ professionals from various backgrounds and disciplines committed to providing quality service. Our technicians communicate with clients to establish a goal for each project and work closely with clients to ensure that the outcome of the service meets their demands and standards. We conduct our services promptly, and our employees provide clients with periodical updates to maintain transparency and trust. Please call us at +1 (888) 287-5227 and request a free quote for our pencil hardness testing.

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