Glossary & Reference
Vickers is the hardness test that scales — literally. One diamond indenter design covers everything from soft aluminum to hardened tool steel to a coating just a few microns thick, which is exactly why it's the scale printed on carbide grade and coating spec sheets across this catalog.
A precisely-shaped diamond indenter — a square-based pyramid with 136° face angles — is pressed into a polished surface under a known, fixed load for a dwell time of 10–15 seconds, then withdrawn. What's left behind is a small, symmetrical, diamond-shaped indentation.
Under a microscope, both diagonals of the indentation — labeled d1 and d2 — are measured and averaged. The Vickers hardness number is the applied load divided by the surface area of that indentation: HV = 1.8544 × F / d² (F in kgf, d the mean diagonal in mm). Bigger number, harder material — same basic logic as Brinell, different math and much finer resolution.
This is what sets Vickers apart from Brinell. Brinell needs different ball sizes and loads matched to different material ranges. Vickers uses the exact same diamond pyramid shape across the entire hardness range — from soft bearing metal to the hardest ceramic — which is what makes it the single most versatile hardness scale in metallurgy.
Because the diamond indent is so small and precise, Vickers reaches a scale Brinell's large ball simply can't: thin materials, small parts, case-hardened surfaces, and — critically for cutting tools — thin coatings. A coating layer is often only a few microns thick; a Brinell ball would crush straight through it, while a tiny Vickers diamond indent stays within the coating itself.
This is exactly the scale used on our Coating page: tungsten carbide substrate typically runs 1,400–2,200 HV, and hard PVD/CVD coatings are reported in HV specifically because Vickers is the only practical way to measure something that thin accurately.