Surface Texture Parameters

Every part's surface is made up of texture and roughness which varies due to manufacturing techniques and the part structure itself. To understand a component's surface and to control the manufacturing process to the degree required in today's modern world, it is necessary to quantify the surface in both two and three dimensions. Surface texture parameters can be grouped into these basic categories: Roughness, Waviness, Spacing, and Hybrid. Terminology Areal- A three dimensional surface area. Cutoff Filter- Determines the wavelength at which the surface structure is differentiated between roughness and waviness data. Proper selection of the correct filter cutoff in software is critical to measurement accuracy. Evaluation Length- The area from which data is obtained. It is a three dimensional area that corresponds to the instrument field of view, or a two dimensional profile that corresponds to the length of the slice as defined in the filled plot. Hybrid Parameters- These parameters are combinations of spacing and roughness parameters. Mean Line- A straight line that is generated by calculating a weighted average for each data point resulting in equal areas above and below the line. Also known as center line. Profile- A two dimensional slice through an area. Roughness Parameters - The finer irregularities in the surface texture which are inherent in the production process. These are a measure of the vertical characteristics of the surface.