After spending a little time honing razors, and getting too hung up on the HHT I think I have finally found the a place for this in my routine.
It won't show you anything that a shave test won't indicate more clearly
However it is useful for me in this way and I hope that this will make it easier for folks starting out to understand the limitations of this test.
Hair comes in many different sizes, coarser hair will pass a razor that may provide a terrible shave. Alternately if you are attempting this test with an extremely fine hair, while a razor that passes this test will undoubtably be extremely sharp, failure with a fine hair does not exclude a razor from being a good shaver.
Just to add to that point your own facial hair will change what type of keenness you are looking for.
Also there are a couple things that may be going on with the edge that passes the hht. What you are hoping for in an hht is to demonstrate the the bevel is thin enough to wedge itself between the layers of hair (if you look at a hair under extreme magnification it you can see them clearly)
on the other hand a false positive for this test may well be due to serrations on the edge.
So at least for myself I use this test with my own arm hair as a prerequisite that a blade must pass before I finish honing it, but not as a final test.
This is how it has worked for me thus far,
Has anyone here gotten a great shave off of a razor that couldn't pass an HHT (given a reasonably coarse hair)?
Cheers- Sailor