Discover Surface Texture Definition & Surface Roughness 3 Methods[PDF]

In this article, we shall study the surface texture Definition and methods to remove surface roughness. We have provided a PDF for the same.

Surface Texture

Surface Texture Definition

Surface Texture, Also known as surface Finish or surface topography, is the nature of the surface, as defined by three characteristics of lay, surface roughness, and waviness. The surface texture is one of the important factors that control friction. Each manufacturing process, (such as the many kinds of machining) produces a surface texture.

Surface Texture Definition

The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial texture. The surface finishing process is Grinding, Polishing, Lapping process, Honing process, etc.

Reasons for controlling the surface texture

  • Improve the service life of the components.
  • Improve fatigue resistance.
  • Reduce frictional wear.
  • Have a close dimensional tolerance on the parts.
  • Reduce corrosion by minimizing the depth of irregularities.

Surface Roughness

Surface roughness often shortened to roughness, is a component of surface texture. It is Quantified by the deviation in the direction of the normal vector of a real surface from its ideal form. It is caused due to the irregularities in the surface roughness. If these deviations are large, the surface is rough; If bey is small, the surface is smooth.

Surface Roughness

Roughness plays an important role in determining, How a real object will interact with its environment. The rough surface usually wears more quickly and have higher friction coefficients than the smooth surface. Roughness is often a good predictor of the performance of mechanical components, Since irregularities in the surface may form nuclear sites for cracks or corrosion. Roughness is also known as a primary texture.

Surface waviness

Surface waviness is known as the secondary texture. It results from the factor such as a machine or work deflections, vibrations, chatter, heat treatment or working strains. Waviness is the component of surface roughness upon which roughness is superimposed.

Surface waviness

Evaluation of surface roughness

  • CLA method
  • RMS method
  • Ten-point height method
Video by Starrapid

CLA Method

  • The CLA method measures surface roughness without physically touching the surface.
  • It involves shining a light source onto the surface and measuring the intensity of the reflected light.
  • The amount of light reflected is related to the roughness of the surface.
  • The CLA method is useful for measuring surface roughness in situations where physical contact is not feasible or desirable.
  • It is a non-destructive testing method that does not damage or alter the surface being measured.
  • The CLA method may not be as accurate as other methods for very rough or very smooth surfaces.
  • It may be affected by factors such as the angle of the light source or the material properties of the surface being measured.
  • Overall, the CLA method is a useful and versatile technique for measuring surface roughness in a wide range of applications.
Photo By Direct Industry

RMS Methods

  • The RMS method involves analyzing the deviations of the surface from its mean plane.
  • It measures the height variations of the surface and calculates the RMS value of those deviations.
  • The RMS value provides a quantitative measure of the roughness of the surface.
  • The RMS method is often used in conjunction with a profilometer to scan the surface and measure its height variations.
  • The RMS method is highly accurate and widely used in industry and research applications.
  • It is particularly useful for measuring the roughness of flat surfaces.
  • The RMS method requires careful calibration and can be time-consuming for large surfaces.
  • Overall, the RMS method is a highly effective and accurate technique for measuring surface roughness, and is popular for many industrial and scientific applications.
Photo By Wikipedia

ten-point height method

  • The Ten-Point Height Method measures the height of the surface at ten evenly-spaced points along a straight line.
  • The method is standardized and measurements are taken using a profilometer.
  • The average of the ten measurements is calculated to determine the roughness of the surface.
  • The Ten-Point Height Method is a useful technique for measuring moderate surface roughness.
  • It is a simple method that can be performed quickly and does not require extensive training or specialized equipment.
  • However, it may not be as accurate as other methods for very smooth or very rough surfaces.
  • The method only provides a rough estimate of surface roughness and may not provide detailed information about surface features.
  • Overall, the Ten-Point Height Method is a useful and widely-used technique for measuring surface roughness, particularly when a quick and easy assessment is required.


In conclusion, surface texture and roughness are important factors that affect the functionality and performance of various mechanical components. The definition of surface texture and the methods used to measure surface roughness have been outlined in this discussion. Accurate measurement and control of surface roughness are crucial for ensuring the quality and reliability of manufactured products.

Therefore, it is essential for engineers and manufacturers to have a good understanding of surface texture and roughness measurement methods to optimize the performance of their products.


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