Curious as to what the advantages/disadvantages are between each of these methods for checking threads. I've got a set of wires, only used them once. Used a couple of O-rings on the ends to hold them to the work when checking, but still seemed to be a cumbersome method.
I like the simple concept of the triangles, but it looks like you're checking across the helix, not the true root diameter. Plus, the sharp edged triangles don't necessarily bottom out at the root of the threads. There are probably charts out there for your target dimension or maybe the simplest way is to measure a known good thread and cut to match? Advantage is, like the wires, they are good for a wide range of threads and diameters.
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The root diameter means little, you are measuring the pitch diameter over wires, the PD is almost certainly the most critical dimension, do whatever it takes to measure this feature.
