Thread: wider bevel=more flex?

Hey all,

So one of my razors, a 5/8" King Cutter, was obviously well loved by it's previous owner/honer, since it has a very flattened spine and now a pretty wide bevel as a result. It does shave well, so it's not out of the rotation yet!

But I have noticed that it doesn't cut as well around the curves as do other razors with a very narrow bevel. All my other razors are hollow also, about 5/8", and are german steel (with the exception of one). I couldn't help but wonder if it's because of the wider bevel. Does this create more flex in the metal at the edge? It would explain why it performs differently around curves, but not on flatter areas where there wouldn't be any lateral force on the edge. It does seem logical, since the wider the bevel, the wider the area of the blade that is sharpened VERY thin....

Just a question I thought of and thought I would see if anyone knows the answer!

P.s. I would love to get a 1/4 hollow razor to try a heavier grind.....I think it would suit my beard type better.

i think a little differently and i am not sure i am correct or not.wider edge could make edge brake easier but sharpness of the blade should be same.Cutting edge is the same thickness .In wider edge as you mention thin part of the blade is more then regular blades edge and support as a result will be less .in this case if you shave heavy beards then it could brake down the edge easier then normal blade..Sharpness of the edge not changes, i agree it will be more flex too.Lets see what others think this is my 0.02 cent

I think the sharpness of the actual cutting edge depends on the steel used, the inclusive bevel angles, and how well they meet (i.e. level of polish/grind). The edge, sharpness wise, doesn't care how much mass is behind the bevels.

Flex-wise, the amount of steel behind the edge (full-hollow vs. wedge vs. "singing" grind) has a major effect on flex, but little effect on edge sharpness. The thinner grinds do sharpen up faster (sometimes) because there is less steel to remove.

Basically, I agree with hi_bud_gl. I just like to make it sound more complicated.

I'm not sure about the bevel flexing, but when it comes to the razor flexing, blades with wider bevels tend to flex less. (Wedges have wide bevels because they are thick and they don't flex; full hollows have narrow bevels because there isn't much metal in there, and they flex a lot.)

In your case, a full hollow, thinly ground razor with noticeable hone wear on the spine, the wider bevel would indicate the possibility of more flex. There is simply less steel behind the edge to keep the blade from flexing.

Try a wedge, get a Wapi from kenrup. It has very good swedish steel and a stiff single concave grind.


Just my $.02,

Couldn't flex be good? It would conform to the countours of your face more.

When I use a wedge I tend to use a bit more pressure., I think the contours of my face conform more to the razor where the full hollows conform more to my face (I get the same results with both but I think I prefer shaving more with a wedge).

Originally Posted by holli4pirating

I'm not sure about the bevel flexing, but when it comes to the razor flexing, blades with wider bevels tend to flex less. (Wedges have wide bevels because they are thick and they don't flex; full hollows have narrow bevels because there isn't much metal in there, and they flex a lot.)

Although wedges may have wider bevels, I think the rigidity (i.e. less flex) of the edge is a result of the thicker grind, not because of the wider bevel.

Hollow grinds do have more flex, but this isn't a result of the bevel width so much as the grind of the razor overall.

If a narrow bevel on a hollow ground razor still has more flex than a wedge razor with a wider bevel, then wouldn't a wider bevel on a hollow make this gap in flex even wider? (metaphorically speaking...)

BTW I have no proof for my ideas, I am merely hypothesizing. But I welcome more disagreement, it makes for interesting conversation. I don't mind being wrong!

Two parameters define the width of the bevel.

1. the bevel angle.
If the angle is smaller (due to a reduced spine) the bevel sides will become wider. The smaller the angle, the more flexible the edge, and it will also be a bit weaker.

2. the thickness of the blade.
A full hollow has a very thin blade, hence a small bevel is to be expected. A wedge has a thick blade, hence it will carry wider bevel sides. In this case the wider bevel will be a bit sturdier, because it contains more steel for the same height. (it has a wider base).

If you see wide bevel sides on a full hollow razor, that always means that the spine underwent a lot of honing wear. The steel of a spine can possibly be softer than the edge. As a result the bevel angle of some razors slowly diminishes over the years of honing. At a given point I believe that will start to have an influence on the durability of the edge. It depends on various other factors, such as beard type, when that starts posing a problem.

If the blade is thin enough to flex, so will the entire edge, for it is even thinner.
If the blade is thick enough not to flex, only a the last bit of the edge is free to flex, from the point where it becomes thin enough to do so.

In my opinion, flex helps the edge to follow the landscape of the skin surface better. At the same time those edges might have problems shaving a coarse, or poorly prepped beard. They have a harder time resisting serious cutting stresses.

Bart.

Originally Posted by Bart

Two parameters define the width of the bevel.

1. the bevel angle.
If the angle is smaller (due to a reduced spine) the bevel sides will become wider. The smaller the angle, the more flexible the edge, and it will also be a bit weaker.

2. the thickness of the blade.
A full hollow has a very thin blade, hence a small bevel is to be expected. A wedge has a thick blade, hence it will carry wider bevel sides. In this case the wider bevel will be a bit sturdier, because it contains more steel for the same height. (it has a wider base).

If you see wide bevel sides on a full hollow razor, that always means that the spine underwent a lot of honing wear. The steel of a spine can possibly be softer than the edge. As a result the bevel angle of some razors slowly diminishes over the years of honing. At a given point I believe that will start to have an influence on the durability of the edge. It depends on various other factors, such as beard type, when that starts posing a problem.

If the blade is thin enough to flex, so will the entire edge, for it is even thinner.
If the blade is thick enough not to flex, only a the last bit of the edge is free to flex, from the point where it becomes thin enough to do so.

In my opinion, flex helps the edge to follow the landscape of the skin surface better. At the same time those edges might have problems shaving a coarse, or poorly prepped beard. They have a harder time resisting serious cutting stresses.

Bart.

Nicely put Bart

Here is my rebuttle to the legend of the Wapi being a thick, beefy grind: