Thread: Why HHT is important or is not?

Obviously the best test is the shave test but not everyone likes testing razors on their faces. I'd like to know the sharpness (HHT) and smoothness (edge magnified) of the edge prior to shaving.

Originally Posted by TucoRamirez

Obviously the best test is the shave test but not everyone likes testing razors on their faces. I'd like to know the sharpness (HHT) and smoothness (edge magnified) of the edge prior to shaving.

That is what arm hair is for

The HHT is notoriously dependent on the actual hair, used for the test.
As such it is pointless to get worked up about HHT 'levels' because they won't compare.

Myy HHT-4 might be your 5, or vice versa. It is pointless to say 'well this guy or that stone can achieve HHT-5' because you have no idea what that means for the person who did the test. that is why the shave test is the only shave that matters. Like the HHT, it is very dependent on the actual hairs on your face. And that's ok, because as long as the razor shaves well on your face, your testing against the thing you are actually using the razor for.

Bruno,

I think you right in regards of hair type. When friend of my visit me once I have ask him for his hair in order to do HHT. His hair pop like charm and without any problem. On other side the same razor ( performed test few days after) and my hair and hair just bend over the blade. My friend hair are thick all the way so looks like they cut easily where mine are soft and very flexible. Maybe that`s why I can`t get any HHT at all when testing my razor with my hairs.

Hello all good people,

just a personal updated... I have spent much more time on C12k stone. I have two stones, two different. one make blade smoother but not really as sharp as expected. Second make very sharp blade.

Now after many more passes on the C12K I can tell that blade performance has changed. Arm hairs are cut more gentle than before. Not much dragging, more sharpness was introduced to blade by extended honing on high grit. I have not strop blade yet, as i had not enough time (I need to sleep too). I`m planning to strop and test blade later today or tomorrow. First if it pass HHT or not and later to check shaving performance.

Best regards

OK, so I don`t not many people is interested in this tread but I took another razor, Shumate Tungsten and I spent several to hone razor from beginning. Several hours on CK12, slow stropping to master perfection and I think I got HHT2 or 3. Not sure about real difference as I do not know how to properly set test in first place. I can say that razor quality has improved dramatically. It became smoother, sharper (I got one nick under nose :-( ) but little more skin irritation. Maybe because my new shave cream. Anyway still doing and mastering honing but saying that I think stropping is even more important. I can see now that stropping is a queen of HHT success...

C12k stones are definitely slow, but several hours may have been overkill..... the good thing is that it is extremely difficult to over-hone on one. I think most will agree that the C12k stones leave a very keen yet semi-harsh edge, or at least mine does (and I think mine is a good one). I'm not sure what kind of stropping you did after honing, but I'd do more of it. If you've got a linen strop, I'd do at least 75 laps on it followed by 100 or 125 on leather. That should tame the harshness. Also, don't go too slowly with your stropping; you don't have to go as fast as Glen does in some of his honing videos, but a little speed helps the edge.

As for how to properly do the HHT, there are directions in the wiki. In them, however, it says to hold the hair with the tip end out. You'll see some say that's wrong and that it needs to be root out. I can get a really crappy edge to HHT-3 when tested root out; what I look for is HHT-3 with the tip of the hair away from me. If my blades can do that, then I know I'm ready for a shave test. As always........ YMMV

Gammaray here...

The HHT information on SRP is very good and addressees most of the issues. I have never commented on the HHT, but I think it is time for me to jump into the fray. I routinely use the HHT test. I have never gotten a GOOD shave from a blade that failed my routine. I have tried it. But passing the HHT is just a test. It does not guarantee a great shave. Only the shave test can do that. However, for the novices I will say that if done properly the HHT, when applied from heel to toe, can tell you if the edge is less than 0.5 microns. Here is a picture of a typical human hair.




Here you can see that an average hair is ~40 microns. The gap between scales is < 0.5 against the grain. The direction that you hold the hair really matters! I know, you think CrO is too course at 0.5 microns, but that is the size of the grain - not the scratch marks. A properly sharpened edge slips quickly between the scales and the the hair falls away without effort or quick cutting motion. My 19 yr. old neice provides me with perfect 20" strands for my testing. These are very reproducicble. I agree with the other cautionary comments that the HHT is not a perfect test. But until we have a better pre-shave alternative I believe it is still the best that we have, second only to the ST.

Gammaray,

thank you for your respond and post. Your comment : "The direction that you hold the hair really matters!" is interesting. So what is correct direction to hold hair. Does all hairs act the same way when hold in the same way.. I mean my wife hairs are very soft and they are difficult to cut. Mine are almost impossible to be used in HHT.

I think the HHT is valuable, as long as it is calibrated to a known hair with a known result. I use my wife's hair, she has thick long straight hair, I know the razor is sharp enough to shave with when it passes the HHT at a 3 or above. The HHT says NOTHING about how smooth the shave is going to be. For me I can get HHT'5 in the 4-5 range with a Naniwa 12K followed by CBN sprays, but it is a harsh shave.


Again for ME, the HHT is a measure of how sharp the blade is, says NOTHING about the smoothness.

I have read many people say they get great shaves from a razor the fails the HHT, I would love to try one of those razors because I have a hard time believing it.

Originally Posted by Doc226

I think the HHT is valuable, as long as it is calibrated to a known hair with a known result. I use my wife's hair, she has thick long straight hair, I know the razor is sharp enough to shave with when it passes the HHT at a 3 or above. The HHT says NOTHING about how smooth the shave is going to be. For me I can get HHT'5 in the 4-5 range with a Naniwa 12K followed by CBN sprays, but it is a harsh shave.


Again for ME, the HHT is a measure of how sharp the blade is, says NOTHING about the smoothness.

I have read many people say they get great shaves from a razor the fails the HHT, I would love to try one of those razors because I have a hard time believing it.

If this how real HHT looks like so I`m even not in door steps. Looks like I will never do my HHT. Guess my blades are not sharp enough.