Surface finishing is a critical term in the industry that describes the texture of the surface. Moreover, it is sometimes also used interchangeably with surface texture. You can find the requirements for surface finishing standards on technical drawings for the mechanical parts. The ASME, or American Society of Mechanical Engineers, have set up surface texture symbols standard that helps in the standardization of surface finishing.

ASME publishes the Y14.36M surface texture symbols standard that highlights specifications and symbols for technical drawings and the B41.6 standard that constitutes definitions and measuring methods for surface finishing. Other bodies to approach for standards and requirements are Canadian Association For Surface Preparation, SAE Aerospace Standards, etc.

Surface finishing standards consist of three different distinct elements comprising of

surface finishing

1. Roughness
2. Lay
3. Waviness

It is common for people to use finishing interchangeably with roughness. Roughness is one of the most common and critical aspects of surface finish. Below are the details about all three elements of surface finishing standards.


In terms of surface finishing, lay refers to the description of the dominant pattern on the surface combined with the orientation of the design. It is generally a result of manufacturing and can be of any shape, including perpendicular, circular, parallel, crosshatched, radial, or others.


Waviness is a common term used to describe the surface finish and refers to the broadly spaced finishing variations. This is because the period imperfections on the surface are comparatively more significant than the roughness. They are also short, small, and regular and thus cannot be considered defects. Some common causes of waviness are warping because of heating, cooling, or machining defects.


Surface roughness, also known as roughness, refers to minuscule irregularities after finishing. It is the most common aspect and parameter used for measuring the finishing. Moreover, many people use the term surface finishing to describe roughness. You can measure the surface roughness by using a profilometer that shows a graph of surface height variations.

How to Measure Surface Roughness

There are different surface roughness measuring techniques and equipment that you can use for the process. Most of them fall into three different categories, as highlighted below.
1. Profiling techniques use a high-resolution probe.
2. Area techniques measure a restrictive or finite area present on the exterior.
3. Microscope techniques help identify roughness by measuring contrasts on the surface.
Importance of Surface Finishing in Engineering

Surface finishing is critical in determining the overall product concurrence within the environment. The surface’s finishing also helps indicate the performance of the various associated components. Moreover, the level of roughness that it might have can also impact the overall effectiveness of the product.

Therefore, engineers and manufacturers must keep track of and maintain the decided surface finishing all the time. Furthermore, it will help them ensure that all the components are consistent and reliable.

And this is where different measurements can come into the picture, as they can help ensure standardization and control of the process. Some of the other critical advantages of surface finishing are as follows.

● It helps in the prevention of corrosion and provides chemical-resistant effects.
● Provides the aesthetic look and feel to the surface and the product.
● It helps with better adhesion features for paints and coatings.
● Ensures removal of any defects.
● It helps with conductivity and also adds surface conduction.
● Increases the strength of the product while reducing wear and tear.

Wrap Up

Surface finishing is a critical aspect of the manufacturing process. It is beneficial to the end user, engineers, and manufacturers. Therefore, it is essential to ensure that the standards of surface finishing are followed to maintain consistency and reliability in the final product. In addition, standardizing the roughness across components and products can be highly beneficial.