Thread: Effect of blade geometry on shave, hht performance

The problem is that i can shave my arm long before I can pass the hht. And with things I would never put near my face, like my pocket knife and kitchen knives. That seems even less reliable

Originally Posted by Rsq

The problem is that i can shave my arm long before I can pass the hht. And with things I would never put near my face, like my pocket knife and kitchen knives. That seems even less reliable

All my pocket knives, and wifes kitchen cutlery will shave hair off legs, arms, you name it. None of them pass the hht, and none are good enough for a face shave either. I am damn new to this straight razor stuff, but I dont see how the arm hair thing is any indication when most common knives after a med ark will take hair off an arm like nobodys business.

If tests like HHT and TPT don't give you enough information about your edge, and you want something other than just shaving with the razor, you should try a magnification. Unfortunately how high of a quality you need is something you'll have to figure out yourself. I know that I can put a good edge on a razor without ever mechanically testing the edge, only observing it in a microscope with good optics, and that the $50 USB microscopes are not adequate for that task. On most razors I can also do it by just observing the water bead in front of the edge during honing, but for consistency I need the high quality optics as well.

Originally Posted by Rsq

The problem is that i can shave my arm long before I can pass the hht. And with things I would never put near my face, like my pocket knife and kitchen knives. That seems even less reliable

A razor off the bevel setting stage on a 1k (norton if you like) will shave arm hair. that doesn't mean it will shave your face, a better gateway test is to see if it pops arm hair against the grain with the razor off your skin maybe 5-6mm.

basically there's 2 arm hair tests.

The TPT is your biggest friend in conjuntion with this. and a loupe helps a lot too.

Originally Posted by Rsq

The problem is that i can shave my arm long before I can pass the hht. And with things I would never put near my face, like my pocket knife and kitchen knives. That seems even less reliable

Originally Posted by ubet

All my pocket knives, and wifes kitchen cutlery will shave hair off legs, arms, you name it. None of them pass the hht, and none are good enough for a face shave either. I am damn new to this straight razor stuff, but I dont see how the arm hair thing is any indication when most common knives after a med ark will take hair off an arm like nobodys business.

Thats because the AHT is for a set bevel, nothing more... once the bevel is true and fully set (not overhoned) then all you are doing to refining the edges as you go.....It really is just that simple...

I think people are overlooking the most important statement made in Glen's first post: calibration.

All test are rubbish. All. They are not shaves. They are simulations, or models, of a shave, at best. And they are poor ones at that. They are a quick and dirty way to ascertain whether you should bother moving onto the next step, whether that be moving to a higher grit hone, or moving to an actual shave.

Their only worthwhile use is in conjunction with rigorous evaluation and calibration to your shaves. You must figure out, for yourself, how a certain test correlates to the shave you should expect. No two people's tests will be the same in this regard. No two razor's tests will be the same in this regard. You need a lot of data to calibrate these tests so that they become useful for you.

In any event, that is how I treat them. I'm not saying the OP's HHT is wrong for him, I'm just saying that as a general thing asking others to interpret your individual test results is like asking someone to comment on how badly your leg hurt when you corked your thigh. They can tell you how much a corked thigh hurt them, but only you can say how much it hurt you.

(Yes, I corked my thigh recently... )

James.

Originally Posted by gssixgun

Thats because the AHT is for a set bevel, nothing more... once the bevel is true and fully set (not overhoned) then all you are doing to refining the edges as you go.....It really is just that simple...

Glen, I can see how you would feel that way but there is more to it than you think.

Thanks Jimbo for adding the calibration comments. That is an important part that was missed. It takes a lot of observations with any test to get usable information from the results and in the end, the shave is where the rubber meets the road.

RSQ, perform both the HHT and shaving arm hairs. When doing the arm hairs go slow, don't just plow them down. Observe how the hairs are cutting. Do one hair at a time at first. The way the hairs cut will give you some degree of smoothness in the shave. Hone until you get past the popping hairs. The arm hair test will give you a test over more of the blade than the HHT will give and if you are cutting arm hairs you just need to refine the edge to give a smooth shave and the HHT can not give you that measurement. The skin on your arm is not as sensitive as the skin on your face so I need to focus to feel a slight tugging which would feel like more on my face. I guess I really don't know what you are trying to achieve.

Originally Posted by Joed

Glen, I can see how you would feel that way but there is more to it than you think.

Actually Joe I was trying to keep it simple and not complicate it sorta like the HHT should have been kept simple and uncomplicated...
When you start trying to get into degrees of sharpness tests, I honestly believe that each person really needs to figure that out on their own with their hair ... The revelation will come with experience instead of us trying to quantify our observations over this media...

what is a corked thigh?

I have coarse, curly hair, so i really need the razor as sharp as possible or I get razor bumps. Thats why i started using a straight in the first place. I like the arm hair popping test and the idea of examining the way the razor cuts one hair at a time