Thread: Apex Width

Would the Apex Width be the same on a Full Hollow as on a Wedge with both grinds having the same bevel angles?

I have to ask this question because the more i think on it the more complicated it is.

An extra hollow grind has to have a finer edge than a near wedge doesn't it? My reasoning is not based on maths but on my face telling me what i have felt over the years..

I would be interested in your thoughts..Thanks

Can get both types of grinds the same amount of sharp though the technique to get there is slightly different. The full hollows I have made are generally more flexible than most vintage full hollows and I experience similar shaving comfort and closeness between those and the 1/4 hollows I’ve made. As far as an apples to apples comparison I have control over every aspect of the build except for the steel content.

Now on to your thought exercise. I can’t see how, given equal parameters that the edge would be any different in profile or how narrow the apex is. I can get to my ideal edge much more easily on a full hollow than a wedge or similar grind. With the ability to flex the edge enough to clear more material behind the edge makes it easier to get your stones to hone all the way out to the edge. Though the idea is no different than changing the tape or adding a strip as you hit your finisher.

I think the biggest perception of difference in edges is most likely located in the hands of the end user.

Originally Posted by JOB15

Would the Apex Width be the same on a Full Hollow as on a Wedge with both grinds having the same bevel angles?

I have to ask this question because the more i think on it the more complicated it is.

An extra hollow grind has to have a finer edge than a near wedge doesn't it? My reasoning is not based on maths but on my face telling me what i have felt over the years..

I would be interested in your thoughts..Thanks

Well that's an interesting observation! My thought is that if the spine were the same thickness on both a wedge and a full hollow, it would be the same due to the angle you would get on the hones. However there are always variables associated with this. Tape on the spine, person doing the honing, and personal preference in defining a finer edge based on comfort level on ones' face, etc.

I don't personally have a wedge so, I can't really give you a more refined answer. I only own hollow ground razors. But what I can tell you is that I look at the spine and see how much hone wear is on it and if it is consistent all the way across. If it is, I usually have a very good edge and lot's of comfort. The edge is fine, but not too fine as to where it folds.

However, I have noticed that when I have uneven hone wear on the spine, the edge is not as pristine and the comfort level drops slightly. I still get a great shave but notice little spots on face that aren't as smooth as the rest of my face.

I hone without tape until I get consistent hone wear along the spine. When that happens, I know the edge is consistent and produces the ultimate edge that is comfortable for my face. At that point, I use linen and leather to keep it in top condition.

I would think that a wedge would be the same, but again I don't have any wedges.

I'm having a hard time following what you are saying as an apex is the very point and has no width. I take it you mean bevel widths. An extra hollow ground razor should have a minuscule bevel width, almost nonexistent. By comparison the same size wedge blade with the same spine width should have a visibly wider bevel width but still not huge. You have to clear away more metal off the sides of a wedge blade to create an apex where the bevels meet than you do with an extra full hollow blade to get the same bevel angle.

Bob

Originally Posted by BobH

I'm having a hard time following what you are saying as an apex is the very point and has no width. I take it you mean bevel widths. An extra hollow ground razor should have a minuscule bevel width, almost nonexistent. By comparison the same size wedge blade with the same spine width should have a visibly wider bevel width but still not huge. You have to clear away more metal off the sides of a wedge blade to create an apex where the bevels meet than you do with an extra full hollow blade to get the same bevel angle.

Bob

No Bob, I mean Apex width.. Everything has a width if you zoom in close enough..

I can now argue for both sides.. Technically the answer seems to be that the apex widths would be the same. However, a wedge has more mass and hollows do feel finer, i am told that is because they are more flexible ....but rigidity is due to mass..Even writing this i am having deeper thoughts.
The wedge bevel touches the hone at a lower level, would that not make for a wider apex..

Apex width would be identical given the same angle and other properties beside the grinding. You're overthinking it imo, mass, flexibility, all that stuff is irrelevant to angle and incidentally apex width. It does affect how the shave feels but that's another matter. :P

Originally Posted by thp001

Apex width would be identical given the same angle and other properties beside the grinding. You're overthinking it imo, mass, flexibility, all that stuff is irrelevant to angle and incidentally apex width. It does affect how the shave feels but that's another matter. :P

This I'd go along with. The apex width would be the same regardless of grind given identical blade and spine widths as the bevel angle is the same. The only way the apex width would be different is if the bevels did not meet to form an apex in the first place as in an unset bevel.

Bob

If you run your thumb nail down the bevel on an extra hollow you can see the bevel flex through the other side, that is the apex flexing also..
A wedge under the same test would not flex. Might that mean that the bevel & apex are thicker, stronger, wider..
Possibly

I can't see a apex having a different width. If its not perfect, its simply..... Dull. Hollow or wedge.

I feel a wedge, has a higher shaving angle, than hollows. I've noticed that if I shaved with a wedge like a hollow, the blade had a tendency to stick to my face.

Originally Posted by JOB15

If you run your thumb nail down the bevel on an extra hollow you can see the bevel flex through the other side, that is the apex flexing also..
A wedge under the same test would not flex. Might that mean that the bevel & apex are thicker, stronger, wider..
Possibly

There's just less supporting material behind the edge bevel so you get that high flexibility although it isn't true that you don't get flex on a wedge.

When I make my own razors, most of which are wedges, they're ground down to an apex before setting the bevel, the metal at the edge is definitely thin enough to flex which I have photos of on some of my threads. I just picked up my small Joseph Allen wedge and the apex flexes under the thumb also, just nowhere near as severely as on a hollow grind and it occurs much closer to the apex because the mass of metal behind is inflexible. It's very small but if you're looking in the light right you can see it. I imagine a lot of wedges have more bevel reveal than they would have had from the factory so there's less hollowing behind their edge bevels than otherwise would be.

It's the sheer thinness of a hollow which allows it to flex behind the apex, the steel there is only about 5 to 7 thou thick sometimes thinner. On a wedge it is much thicker of course.

Are you getting more of a preference for the hollow grinds?