Knoop Hardness
The Knoop hardness is the measure of the Knoop hardness test, a micro-hardness test for mechanical hardness used particularly for very brittle materials or thin sheets, where only a small indentation may be made for testing purposes.
The Knoop hardness equals the applied force divided by the length of the long-axis indentation squared and the correction factor.
Formula
![Copy to Clipboard QuantityVariable["HK", "Pressure"] == QuantityVariable["P", "Force"]/(QuantityVariable["L", "Length"]^2*QuantityVariable[Subscript["C", "p"], "Unitless"])](https://www.wolframcloud.com/objects/resourcesystem/marketplacestorage/resources/e53/e53cec8c-d9d0-406b-97a4-5f1f72aa7658/Webpage/FormulaImage.png)
| symbol | description | physical quantity |
|---|---|---|
| HK | Knoop hardness | "Pressure" |
| L | length of long-axis indentation | "Length" |
| P | applied force | "Force" |
| Cp | correction factor | "Unitless" |
Forms
Examples
Get the resource:
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Get the formula:
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Use some values:
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