# Understanding How To Measure Surface Finish

Surface finish is the primary indicator for how well an object or part will interact with its environment over time. Surface roughness measurements will provide reasonably accurate indications of how mechanical components will perform. There are two ways to measure surface finish. One way is called skidded and measures roughness only. The other way is called skidless and records a combination of form, waviness, and roughness. Learn more about measure surface finish and why it is even measured at all.

Surface Finish

Surface roughness, lay or form, and waviness are the top terms for measuring surface finish. These measurements are necessary to determine the dimensions of a surface that is anything other than a completely flat plane. Understanding how to measure surface finish is integral for controlling layer formation transfers and friction for manufacturing in machining.

Surface Measurements

Taking the surface measurements helps manufacturers make more money and produce less waste. When determining which inserts are best for milling projects, buyers will often compare the surface finish measurements to compare and contrast product choices. Ceramic inserts for milling may be measured for roughness with a skidded system. In contrast, carbide turning inserts are better suited to the skidless system to determine roughness, waviness, and form.

Surface Geometry

The principles behind measuring surface geometry are two-fold, but both are based on the streamlining of manufacturing. Surface geometry measurements attempt to predict the long-term performance of essential machine parts such as end mills or saw tips. Surface geometry measurements also attempt to use controls to streamline the manufacturing process in the future.

Surface Arithmetic

The accepted standard of measurement is the arithmetic average roughness. Determining roughness by arithmetic average has measurement options in both English and metric units. English provides measurements in microinches, and metric units provide measurements in microns. Averaging and profiling instruments are used to measure surface profiles. However, only profile instruments can also determine waviness and form. Ra typically presents the surface finish value in microinches.

Surface Calculations

There are basic calculations meant to produce surface finish measurements. Once these values are determined, the manufacturing details can be better projected for the long-term efficacy of a piece or part of a mechanical component.

• Inches per revolution
• Surface finish

Surface Predictions

Using surface measurements allows for the predictability of the efficacy of mechanical components. This detailed knowledge is essential for staying on top of industry advances and tooling solutions. Companies need reliable mechanical parts on their end to complete the tasks for productivity and profit margins. Industry production relies on the long-term performance of components to continue manufacturing and setting industry standards.

Kennametal produces mechanical components across multiple industries and has for decades. They use cutting-edge technology and surface measurement as a trusted production giant. Attention to detail and accordance with all applicable legal requirements means that safety data sheets meet necessary system requirements for operation in the US and other countries.

Kennametal is a long-established innovator providing solutions and support to multiple businesses within several different industries.