Bevel Chart

I made up this chart for messing with the spine thickness of my Gold Dollar mods. I found it handier than messing with a calculator every time I want to check my progress. The chahrt covers most every reasonable GD66 situation. Maybe someone else will find it useful.

The Bevel Width is the distance from rhe edge to the far side of the honed flat on the spine. Thickness is the thickness of rhe spine, measured at rhe far edge of the honed flat on the spine. usually this will simply be rhe thickest point on the spine. I redid it in metric for rhe benefit of rhose poor unfortunates without a vernier caliper graduated to 1/128".

Very interesting, I'll be sure to keep an eye on those when I try to figure out my favorite angle!

Slash McCoy said:

View attachment 344936
I made up this chart for messing with the spine thickness of my Gold Dollar mods. I found it handier than messing with a calculator every time I want to check my progress. The chahrt covers most every reasonable GD66 situation. Maybe someone else will find it useful.

The Bevel Width is the distance from rhe edge to the far side of the honed flat on the spine. Thickness is the thickness of rhe spine, measured at rhe far edge of the honed flat on the spine. usually this will simply be rhe thickest point on the spine. I redid it in metric for rhe benefit of rhose poor unfortunates without a vernier caliper graduated to 1/128".

Click to expand...

Man...you've got alot of time on your hands!

Ok, ok, ok. I'll be the stupid one in the class who raises his hand and says it:

"Slash, sir? I don't understand. How does one read and use this table?"

If you don't mind, imagine that you're explaining it to a precocious third grader and then I'll have a chance at understanding.

18.6 mm blade with 5.5 mm wide spine, gives 17 degree bevel angle.

Gamma said:

18.6 mm blade with 5.5 mm wide spine, gives 17 degree bevel angle.

Click to expand...

And one wants to be with in what range? I seem to remember a maximum of 18, but don't remember the minimum.

Typically, no less than 15* inclusive.


-Xander

What is labeled on the chart as 'bevel width' is really blade width. So if you have a 6/8 razor, it will be very close to 19mm wide. Measure the spine and cross that number (spine thickness) with the blade width and the number where they cross is the included angle of the razor. The included angle means it is the angle between the two sides of the razor, or the angle of both 'halves' of the razor added together. This is confusing because the bevel angle of knives is always given from the centerline, or one- half of the included angle. To expand on that, when you lay a straight razor down to hone it, the angle generated is the angle from the centerline to the side of the bevel resting on the hone. That is also the angle you would raise a knife off a hone to sharpen it. The included angle is double that because it refers to both angles from the centerline.

Brian

oakeshott said:

Ok, ok, ok. I'll be the stupid one in the class who raises his hand and says it:

"Slash, sir? I don't understand. How does one read and use this table?"

If you don't mind, imagine that you're explaining it to a precocious third grader and then I'll have a chance at understanding.

Click to expand...

Excellent question.

Double edge razor blades have included angles larger than 20 degrees and they seem to work well even when used as a straight razor (shavette or similar). The thinner the blade and the smaller the bevel angle the sharper the edge could be theoretically but in practice it does not seem to make any difference once under something like 24 or 25 degrees. The shallower the angle, the weaker the very edge of the blade will be too so the less durable it will be. At a glance, the ideal angle would seem to be the greatest angle possible that will yield an edge sharp enough to shave comfortably with but that may not be how it really works. It certainly seems that a wide range of bevel angles are acceptable judging by the wide range used on different razors. I am curious too as to what information someone may contribute to your question.

Brian

oakeshott said:

And one wants to be with in what range? I seem to remember a maximum of 18, but don't remember the minimum.

Click to expand...

I think the angle is one of those things that a person needs to just try and see what they like and what works best. We have all heard of and many experienced that razor that just seemed to shave well.

Could be the angle for that blade just suits the way you shave???

I enjoy playing around with the angle, and you can certainly change the way the edge feels to some degree (no pun intended) . Helps when you have a razor that you can add a few layers of tape to and not get too far off the chart

Nice resource, thanks.

I use bevelcalc all the time.

daflorc said:

Man...you've got alot of time on your hands!

Click to expand...

nah. Did it with an ooen office spreadsheet. then took a screenshot amd made a jpg.

oakeshott said:

Ok, ok, ok. I'll be the stupid one in the class who raises his hand and says it:

"Slash, sir? I don't understand. How does one read and use this table?"

If you don't mind, imagine that you're explaining it to a precocious third grader and then I'll have a chance at understanding.

Click to expand...

look at your blade. Look at the flat strip worn into the spine by honing. This is part of the bevel plane, same as the bevel at the edge. The bevel width is the distance from a point at the razors edge to rhe corresponding point at the far edge of the spine bevel flat. NOT the widrh of the blade. This measurement is the hypotenuse of a solvable right triangle that gives us half the bevel angle. The thickness is the thickness of the spine measured at that same point on the back edge of the spine bevel flat. That measurement is twice the length of another side of the solvable right triangle. So take those two measurements and enter the table and you get the bevel angle

BDF said:

What is labeled on the chart as 'bevel width' is really blade width. So if you have a 6/8 razor, it will be very close to 19mm wide. Measure the spine and cross that number (spine thickness) with the blade width and the number where they cross is the included angle of the razor. The included angle means it is the angle between the two sides of the razor, or the angle of both 'halves' of the razor added together. This is confusing because the bevel angle of knives is always given from the centerline, or one- half of the included angle. To expand on that, when you lay a straight razor down to hone it, the angle generated is the angle from the centerline to the side of the bevel resting on the hone. That is also the angle you would raise a knife off a hone to sharpen it. The included angle is double that because it refers to both angles from the centerline.

Brian

Click to expand...

No dont use rhe blade width. Measure from the back edge of the spines bevel flat to thw very edge of the razor. If you use the width of the entire blade you will be way off.

oakeshott said:

And one wants to be with in what range? I seem to remember a maximum of 18, but don't remember the minimum.

Click to expand...

Thats one of those YMMV things but I love a GD66 with about a 16-1/2 degree bevel. It is a wicked shaving beast! Out of thw box and straight to the bevel setter the angle is over 18 degrees and it shaves well enough but it is like the difference between a Buick Roadmaster and a Corvette. Anyway most of my mods I now thin down to under 17 degrees. I will PIF one or two when I get home from Greenland.

Slash - I might try grinding down the spine on a GD I have. I have a grinder in the garage, do you think I can get good results from that? Or, would you recommend sticking to sandpaper?

Sandpaper glued to marble tile has advantages over an ordinary bench grinder. First of all, you are maintaining a flat bevel plane because the sandpaper is flat. Second, you can use the edge of the razor as a guide so that the edge and spine remain in alignment. If you had a knifemaker's type belt grinder, you could set up a jig to do it, I suppose, but no, I would not attempt that on a bench grinder. If you do, and it comes out good, please post. But sandpaper doesn't take all that long if you start with 60 grit and use plenty of pressure, and knock the swarf out of the sandpaper before it loads up. A file card (actually a sort of brush, for cleaning files) helps with coarse sandpaper. This also works good for thinning the tang and for obliterating the stamping.

A bench grinder can be used for some things, such as re-profiling the nose or flattening the back of the spine for etching or engraving, for instance to put the day of the week on a razor in a 7 day set. They do heat up a razor quickly, though. You can get the blue stain of death in only a couple of seconds.

If it is not variable speed, I wouldn't use it on razors at all. YMMV.

If you want to use machinery, you can try clamping a belt sander upside down in your vise and running it on slow speed with maybe a 100 grit belt. You will want to make an edge protector out of a folded piece of thin sheet metal. Several, actually, because you will wear through them.

Good advice, thanks. I'll stay away from it. I figured I could line up the wheel with the curve of the hollow and thin it out a little but I didn't think about heat. I'll give the sandpaper a shot first. That's my only complaint about a GD... I don't like the width of the spine.

Just remember that if you thin down the spine, you MAY want to thin the shank as well. YMMV but I prefer the spine to be the thickest part of the razor so no step or shoulder can develop from honing. Yes it is a good idea to push the hollowgrind up into the spine a little bit, but I use the sanding drums on the Dremel, followed by hand sanding with 60 or 100 grit.

Slash McCoy said:

View attachment 344936
I made up this chart for messing with the spine thickness of my Gold Dollar mods. I found it handier than messing with a calculator every time I want to check my progress. The chahrt covers most every reasonable GD66 situation. Maybe someone else will find it useful.

The Bevel Width is the distance from rhe edge to the far side of the honed flat on the spine. Thickness is the thickness of rhe spine, measured at rhe far edge of the honed flat on the spine. usually this will simply be rhe thickest point on the spine. I redid it in metric for rhe benefit of rhose poor unfortunates without a vernier caliper graduated to 1/128".

Click to expand...

Do you have it in 1/1000ths of an inch ... I have an old micrometer.