Thread: deeper blade = sharper razor?

I`ve been thinking about the trigonometry of a razor. If the spine of a razor is the same width no matter what depth the razor.
Then when honing the razor the angle at the edge of a deeper blade would be much shallower than that of the smaller razor.

I don`t have that much experience in the world of razors maybe deeper razors have thicker spines. I would be interested to find out either way.

this is a math problem - the ratio between the spine and the width is also known as the bevel angle.
there are several big threads on this, along with many actual measurements.
look them up.

bart from coticule.be has an angle calculator that works great for that sort of thing.

Larger razors tend to have thicker spines. There is some variation in bevel angle among razors, but there are big razors with narrow angles and big razors with wide angles. Most razors seem to be somewhere in the range of 15 to 18 degrees.

Yeah, as gugi stated, this has been combed over before. I have razors that are less that 1/2 inch wide with spines you could almost sharpen and shave with, and 8/8 blades with a spine over 1/4 inch wide. It is relative to the optimal bevel angle, and a very interesting topic to research. I have a few razors that have relatively narrow spines that I want to try narrowing to less than 4/8 just to see if the loss of blade width throws the geometry off enough to alter the edge. Happy hunting!

Might want to read about real razor angle measurements right here


http://straightrazorpalace.com/razor...zor-angle.html

Degree of hollow grind, I feel is more of a factor of sharpness. No scientific proof, just my experience.
lesser bevel angle can equate to bigger bevel, so number of geometrical factors to consider. Full hollow and singers, extra hollow seem to get better with initial few hones in my experience.

It has been explained to me that the ratio of spine thickness to blade width should be between 3 and 4 with 3.5 (whoda guessed) a reasonable average. So a 7/8 razor should have a spine thickness of about .250" and 6/8 would want a .215" spine, where a bit thicker is OK. For honing, thinner spines than that seem to allow for more delicate edges which can be frustrating for us apprentice whetters to successfully deal with; the journey and master level honers among us may not be as potentially vexed.

Again I mention that one should really read that thread I linked with actual measurements where it will become apparent rather quickly that there are no hard and fast rules or ratios...
The numbers are really all over the place but the average seems to be about 16 degrees as to the "Best" I really would not venture a guess...

The angle and bevel width in relation to sharpness has no relation, the quality of the steel is much more important... Razors only get so sharp, period and many/most can get there, the only question is how smooth they are at that sharpness level...


BTW please feel free to add more measurements to that thread, as you can see the more data we have, the better the conclusion becomes...

Originally Posted by blockhead

I have a few razors that have relatively narrow spines that I want to try narrowing to less than 4/8 just to see if the loss of blade width throws the geometry off enough to alter the edge. Happy hunting!

I've had razors from 7 1/2 degrees up to 25 degrees. Below about 16 degrees the edge doesn't hold up as long but does seem to be sharper. Above the normal range the razor still seems to shave fine, but the razor is heavier than it needs to be. That one razor with the 7 1/2 degree edge was absolutely sick for about two strokes, at which point big chips started appearing in the edge. My Hart has a 13 degree angle and won't hold an edge for more than about 5 shaves. And on the upper end of the scale I've got a razor that I had Josh Earl make me that is a 5/8 with a 25 degree honing angle, that shaves fine and holds an edge fine, but weighs nearly as much as a 7/8. The commercial guys all seem to have gone with steep angles as well - Gillette cartridge blades have a 28 degree honing angle on them, and apparently the Feather blades have a 25 degree angle.