Radius gauges
Radius gauge in thousandths of an inch.
I use these gauges to measure the corner fillets on components when I am designing. I was unable to find a simple tool like this and this was one of the first things I designed. For all my projects to date the .025 steps have been more than accurate enough. They are a cheap easy print that greatly reduce design time.
Here is the match in metric. It is graduated in 1mm steps from 6MM-12MM and .5MM steps from 1.5MM-5.5MM I honestly have never used it because the majority of my designing is using US standard gauge.
Here are my gauges printed in HATCHBOX BLACK PLA. I believe I printed them at .16MM layer height and 15% infill.