Surface texture parameters tell so much about a surface and how it might perform. But just looking at the equations can’t tell us everything we need to know about how to interpret the values. This new, free series of videos helps explain the meaning of dozens of common surface texture parameters in a simple and graphical way. … Read more
Is it really 2–50 UPR? Don’t be so sure! Whether rolling, sliding, sealing, or simply fitting together, round geometries are everywhere. And controlling the shape of these “ideally round” surfaces is critical to their performance. Historically, roundness has been specified and controlled as what can be described as “waviness around a circle.” Higher frequencies are … Read more
Defaults in standards rarely apply perfectly in all situations. That’s the case with ASME Y14.5-2018 (Section 4.1, Fundamental Rule ‘S’), which states: Unless otherwise specified, elements of a surface include surface texture and flaws (e.g., burrs and scratches). All elements of a surface shall be within the applicable specified tolerance zone boundaries. But what if … Read more
This is the second Case Study in our series on the new ASME Y14.49 supplemental standard. An engine cylinder bore is one of the most critical surfaces/geometries in the world. Courtesy QMP Racing The interface between the bores and the mating piston rings is essential to 90% of the world’s transportation…and is responsible for approximately … Read more
The ASME Y14.5 standard is a foundation for geometric dimensioning and tolerancing (GD&T) around the world. It provides methods for communicating part sizes, geometries, orientations, and positions. The primary language of Y14.5 is centered around concept of zones and “fit.” But what if “fit” isn’t the function we are working with? When we’re talking about … Read more
In a recent article we talked about applications where a stylus may be the best measurement option and others where optical measurement is preferable. Here’s another interesting case: a Mahle HV385 thermal spray coated piston ring, courtesy of Andy Durham from Durham Racing Engines. Measuring the piston ring with an optical 3D profiler Here is … Read more