Beginning some 30 years ago, portable surface finish gages—some small enough to fit in a shirt pocket—brought a new level of part control to the manufacturing floor. Bringing surface finish inspection out of the lab and onto the floor was important for a couple of reasons. For the previous 50 years, part dimensional tolerances had been shrinking. As a result, surface finish and form irregularities were eating up an ever-increasing portion of overall dimensional tolerance, a trend that continues today. It had also become clear that surface finish played a very important role in the performance of the part. The unique characteristics of a surface could determine whether paint stayed in place, lubrication held or leaked, or how much “noise” was produced when surfaces moved against each other.
With proper locating and fixturing, small portable surface finish gages can measure surface finish parameters easily, usually with the touch of a single button. Like dimensional hand tools, general-purpose portable surface finish gages provide easy-to-use and reliable results for many applications. Simply place the pocket-sized gage on the part so that its built-in rest pads locate it in place, press a button, and your results pop up, ready to be compared to the requirements.