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 compatibility. Ernest Rabinowicz went to great lengths to understand the relationship between material properties and wear, to determine the characteristics that work best in sliding … Read more
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 would build up a measurement lab to support large volume surface roughness measurement—purchase a number of instruments, hire employees, etc. I asked an engineer friend … Read more
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 scale most surface texture features are gradual enough to easily be traced by a 90-degree stylus measurement probe.
So many wear mechanisms…so many definitions “Wear” is the progressive modification to a surface. It may result in a loss, deposit, or redistribution of material[1]. Quantifying different types of wear can be challenging. we can name literally dozens of wear mechanisms and terms to describe them, many of which overlap or even contradict. Three terms … Read more
For those of you who have taken my class, you know that this is an important resource for me. Ernest Rabinowicz really pioneered our understanding of friction and wear, both from a surface texture point of view, but also from a materials point of view. This book pulls it all together. Rabinowicz’s empirical work led to … Read more
Over the years we’ve shown these images frequently on our website (which has just been updated, by the way!). Taken together, they sum up the kinds of issues we see—and help solve—every day. Ever wondered what these measurements are actually showing? In today’s post we take you “behind the curtain” to see the story… Leaks … Read more
It’s a regular refrain on this blog: surface texture consists of a spectrum of spatial wavelengths, ranging from shorter spatial-wavelength roughness through longer spatial-wavelength waviness and form. Through the process of filtering, we divide the spatial wavelengths into what we will call roughness, waviness, and form for a particular application. Filters are applied at specified … Read more
Many companies use both stylus and optical measurement technologies to measure surface texture. A question that we are often asked is, “Can the measurements between these different systems correlate, and can they produce the same numbers?” The starting point for answering these questions is to consider the limitations of each instrument. The chart below highlights … Read more
How would you go about measuring these coins? In terms of value, the most precious would likely depend upon your age, and possibly the time left on your parking meter! In terms of surface texture, the measurement method will also depend on the application… 2D vs 3D instruments If you are coming from the world … Read more
Surface Roughness, Texture, and Tribology Classes “This was one of the best classes I have ever taken. It really helped me understand surface texture and simply it made me a better inspector. It helped me see the bigger picture. I guarantee you’re going to want to learn more.” Agustin Guzmán, Inspector at SpaceX Next Class: … Read more