3D Surface Roughness and Wear Measurement, Analysis and Inspection

Welcome to the Surface Roughness Analysis Blog

Why do brakes squeak? When will a gasket leak? What caused the haziness in my painted finish?

Surface texture and function are tightly linked. Understanding the relationship between texture and function, and sharing that information with engineers and quality professionals, is what Michigan Metrology is all about. 

The articles in this blog explore the concepts of surface texture analysis and measurement. We show how you can apply these concepts to solve problems related to leaks, squeaks, appearance, wear, noise, fit, friction, vibration, adhesion, and many other functions.

Looking for more information on specific surface texture parameters? Visit our Surface Texture Parameters Glossary for an introduction to dozens of 3D surface roughness analysis parameters.

And, if you want to learn much more about surface texture consider attending our online and in-person classes for an immersive introduction to the many concepts in surface analysis.

bearing ratio parameter ratios, spk/sk, svk/sk, spk/svk surface texture parameters

Ratio Parameters (Spk/Sk, Svk/Sk, Spk/Svk)

November 30, 2022

Tracking the ratio of several bearing ratio parameters can provide information about the symmetry of the surface texture, which can sometimes be more important than the amplitudes of the peaks

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Benoit Mandelbrot and fractal mathematics

Remembering Benoit Mandelbrot

November 16, 2022

Benoit Mandelbrot, whose birthday we commemorate on November 20, found commonality in the math that describes patterns and distributions in nature and modern life. Mandelbrot saw order in phenomena that

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ASME B46.1 standard for surface roughness, waviness, and lay

What is ASME B46.1?

November 8, 2022

The American Society of Mechanical Engineers’ ASME B46.1 standard defines surface roughness, waviness, and lay, as well as parameters for specifying and controlling surface texture. Learn what it covers and

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surface roughness cutoff wavelengths - surface texture filtering - michigan metrology

What do you do if you don’t know the cutoff length?

November 1, 2022

Cutoffs define the band of spatial wavelengths that will be included in the calculation of surface texture parameters. Per specifications, the cutoffs must be specified. So, what do you do

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Anton van Beek Advanced Engineering Design is an essential engineering resource for tribology and surface metrology.

Advanced Engineering Design: Lifetime Performance and Reliability

October 25, 2022

In my office I have dozens of books that I consider primary engineering texts. But there are a few that I consider essential. Anton van Beek’s Advanced Engineering Design is

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Sa does not equal Ra!

October 18, 2022

Download this article as a PDF Ra, the roughness average (or average roughness), is the average of the surface heights along a measurement trace. Sa is the average roughness over

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Why does paint appear glossy or matte?

October 5, 2022

Some paint finishes are purposefully glossy or shiny. Others appear matte, or dull, or hazy. So, what leads to the difference…and what do all these terms really mean? Texture scatters

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Scale of interaction for surface roughness analysis and the surface texture measurement system (stylus gage, optical profiler) depends upon the application

The scale of interaction

September 27, 2022

I live in a world that is 1 mm x 1mm, and often less than 20µm high. It’s amazing, all of the physics that goes on in such a tiny

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Wear - Material Property Relationship,Adhesive Wear,Metalurgical Compatibility,sliding friction, ernest rabinowicz, friction and wear

Why are “incompatible” surfaces better for sliding friction?

September 19, 2022

Key concepts in tribology have often been discovered by trial and error…then made more broadly useful through rigorous work that uncovers the broader understanding. Such is the case of material

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Donald Cohen of Michigan Metrology is an expert in surface roughness, surface texture, 3D surface roughness measurement and tribology

A little tribology every morning

September 13, 2022

Years ago, I’d just completed one of my first major surface roughness measurement projects, and I was considering my next steps to form an actual business. I thought that I

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Rpc, or Stylus (X,Y) Pc surface roughness parameter measures the number of peaks per unit length of surface texture.

Parameters Primer: Rpc, or Stylus (X,Y) Pc

September 6, 2022

Rpc is the Peak Density in the X or Y direction of surface texture data. It is a measure of the number of peaks per unit length (i.e., peaks/mm) in

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Scaling vs autoscaling (auto-scaling) in 3d surface roughness measurement data - Michigan Metrology

Scaling and Auto-Scaling

August 29, 2022

The vertical scale of most surface roughness data is highly exaggerated so that the detail can be more readily discerned. In reality, the actual slopes are fairly gradual. At 1:1

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