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# Vmc (Core Material Volume) | Area Roughness Parameters

## Description of surface texture parameters in ISO 25178

• Height
• Spatial
• Hybrid
• Functional
• Functional volume
• Feature

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## Vmc (Core Material Volume)

Vmc (core material volume) represents the difference between the material volume at areal material ratio q% and the material volume at areal material ratio p%. It can also be used to quantify the magnitude of the core surface, reduced peaks, and reduced valleys based on volume parameters.

Vmp, Vmc, Vvc, and Vvv represent the volumes of the reduced peaks, core material, core void, and valley void respectively.

To use volume parameters, the areal material ratio values that divide the reduced peaks and reduced valleys from the core surface must be specified. By default, 10% and 80% are used.

## Find from the parameter list

Height Sa (arithmetical mean height) Sz (Maximum height) Sq (Root mean square height) Ssk (Skewness) Sku (Kurtosis) Sp (Maximum peak height) Sv (Maximum pit height) Sal (Auto-correlation length) / Str (Texture aspect ratio) Std* (Texture direction) Sdq (Root mean square gradient) Sdr (Developed interfacial area ratio) Smr(c) Areal material (bearing area) ratio Smc(mr) Inverse areal material ratio Sk(Core height) Spk (Reduced peak height) Svk (reduced dale height (reduced valley depth)) Smr (Peak material portion) Smr2 (Valley material portion) Sxp (Peak extreme height) Vvv (Dale void volume) Vvc (Core void volume) Vmp (Peak material volume) Vmc (Core material volume) Spd (Density of peaks) Spc (Arithmetic mean peak curvature) S10z / S5p / S5v / Sda(c) / Sha(c) / Sdv(c) / Shv(c)