HHT puzzle...

After doing the pyramid on my Naniwa 5/8 my razor is passing the HHT test. After polishing on the C12 it no longer pass the HHT test!!!

After stropping it will again pass the HHT test!!!

Any explanation please???

At the 8K point the "teeth" are probably grabbing the hair & popping it. 12K is smoothing them out & refining them, so it's not such an aggressive edge & less able to grab. The strop probably refines it enough to catch the hair again.

Damn that accursed HHT & it's lack of consistency & usefulness to the unwary!

That made a lot of sense to me. Thanks.

I couldn't get a prof honed blade to cut hair at all - on one that was taken through a 30k shapton. In my case, it was not knowing all the hair prep - oil free (washed), wet, held by the end and cutting towards the folicle, etc. When I learned that & got a fresh strop, I could cut chest hair on all blades. Head hair is so fine, it was spotty. I now use chest hair to know when I'm in the ballpark, and head hair to confirm I'm there.

The HHT can be very inconclusive at times. Some razors I have honed on high end finishers will not pass it and still provide excellent shaves, while others I have set bevels on an 800 grit King have passed HHT, as Ben quite rightly mentioned the 'teeth' are capable of catching hairs.

Now, an 800 can pass HHT, but I definitely would not want to shave off it! Do not be fooled, this does not mean a razor is shave ready - it just means it has an established bevel with enough 'teeth' to catch a hair.

You have to know how to read a true HHT, which is passed by the hair literally falling in half upon contact without pressure. The razor will 'grab' the hair and it will split. But even so, a razor could still be perfectly shave ready and not pass HHT.

It is a parlour trick and do not be too concerned about it. All hair is different, which is yet another variable.

Quote:

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Originally Posted by pinklather

I couldn't get a prof honed blade to cut hair at all - on one that was taken through a 30k shapton.

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I too have had more than a couple pro-honed blades not be able to pass the HHT, yet the shave was nice. Another vote (from me) that not a lot of emphasis should be placed on the HHT.

I agree that the HHT is not that useful as a random test on a random edge. But I find it very useful when I hone, along with other tests.

If you are going to use it you need to put in a lot of work to assess how it relates to your shaves - test, shave, assess. Repeat. A lot.

James.

Yeah yeah. The HHT is a trick... soo I guess that makes me a magician...
the Amazing Oz :roflmao

It is not that it is a trick, but it is meaningless to someone who does not know how to use it.

I advise that one should not be too concerned about it.

Of course the shave test is the only test to be concerned about but all the other tests, HHT included are a useful guide.
There is an in depth Wiki article on HHT for those having trouble with it :
Hanging Hair Test, from trick to probing method - Straight Razor Place Wiki

The HHT is useful when you know what you're dealing with. I can't help but feel it's of less use to the inexperienced.
The Wiki article is a good guide on gaining an understanding of how to use it to assess the edge, but for many of those new to the game, it can either pass the HHT, or it's not honed right, & that's the problem.
Personally, I must admit I do incorporate it, but I don't consider a pass to be the benchmark of a finished blade.