Seeking answers regarding blade bevels, grinds and sharpening terminology

J

jumpman

Joined
Aug 10, 2011
Messages
172
Hi everyone,

I am relatively new to sharpening and have tried multiple systems including some fixed angle and more recently, freehand methods. My question is involving the terminology relevant to many of the aspects of this process. I have researched the issue and found different information regarding the same terminology. I am going to throw some basic terms in there as well to hopefully cultivate some more complete answers. I have pieced together what seems to make sense to me but I would like to hear from any experts who can clarify the issue in the simplest terms possible...

I am aware there are some different schools of thought on this issue and because of this there may be no definitive answers, but referring to knives in general my question is, to anybody who feels they know, what is exactly meant by the following terms...

Blade grind, bevel, primary bevel, secondary bevel, tertiary bevel, micro bevel, shoulder, back bevel and edge bevel.

Sorry if this has already been beat to death in a couple places but I figured this may be a good place to get it spelled out all at once. Thanks to anyone who contributes, I really appreciate it. Also if anyone has any additional relevant tips or terminology I would appreciate that as well. Thanks again everyone.
 
Blade grind = the complete grind of the blade that shapes it's body. Such as, Flat grind, Saber grind, Convex grind, and so on.

Bevel, edge bevel = the sharpened part of a knife where the cutting occurs.

Primary bevel = multi meaning, could refer to the blade grind or the upper bevel when using a micro bevel.

Secondary bevel = multi meaning, could refer to the to the edge bevel or the microbevel on a edge bevel.

Tertiary bevel = Never heard of it.

Micro bevel = a very small bevel at the apex of a edge bevel.

Shoulder = the transition point between the bevel and blade grind.

Back bevel = a term used by wood workers for plane irons though could refer to the area behind the apex.


Other common terms.

Apex = the point where the bevel slopes reach infinity.

Bevel slopes = Each side of the sharpened bevel. Two slopes = a cutting edge.

Burr = plastic deformation of metal caused by heat, pressure, and abrasive wear.

Check my sig line for some links to helpful threads.
 
Tertiary bevel=micro bevel on a tradionally sharpened knife. I.e. third bevel.


-Xander
 
Not a triple beveled edge, but a micro bevel on a V ground edge on a flat ground knife. Or to describe any third in progression item by level of importance ... primary(#1) secondary(#2) and tertiary(#3).


-Xander
 
fast14riot said:
Not a triple beveled edge, but a micro bevel on a V ground edge on a flat ground knife. Or to describe any third in progression item by level of importance ... primary(#1) secondary(#2) and tertiary(#3).


-Xander
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And if you really want to go crazy with additional bevels:

( from site: http://oxforddictionaries.com/words/what-comes-after-primary-secondary-tertiary )

"What comes after primary, secondary, tertiary?

The sequence continues with quaternary, quinary, senary, septenary, octonary, nonary, and denary, although most of these terms are rarely used. There's no word relating to the number eleven but there is one that relates to the number twelve: duodenary."
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Regardless of the answers you get here... you pretty much gotta define them or figure it out from context... they're too often interchanged in use. Just like angles.. when some post 20 deg. they mean per side, others mean inclusive or the total angle. ;)
 
Chris "Anagarika";11260437 said:
Murray Carter uses primary edge for the secondary bevel, and secondary edge for primary bevel. Confusing?
Click to expand...

Rather;

Primary Edge, the edge that initiates the cut

Secondary Edge, the edge that pushes through the cut
 
Obsessed with Edges said:
And if you really want to go crazy with additional bevels:

( from site: http://oxforddictionaries.com/words/...ndary-tertiary )

"What comes after primary, secondary, tertiary?

The sequence continues with quaternary, quinary, senary, septenary, octonary, nonary, and denary, although most of these terms are rarely used. There's no word relating to the number eleven but there is one that relates to the number twelve: duodenary."
Click to expand...
Click to expand...

lol I wonder how long its gonna take for someone to go and put a senary bevel on their knife. I've already heard of putting multiple bevels on a chisel.
 
Hey everyone, thanks so much for the great responses so far. Been really busy lately, when I get a minute I've got a few things to add to the convo but I just wanted to say thanks again.
 
Curtis_Lowe said:
lol I wonder how long its gonna take for someone to go and put a senary bevel on their knife. I've already heard of putting multiple bevels on a chisel.
Click to expand...

I once saw a cheap Chinese copy of a higonokami (sp?) knife. The blade had 5 bevels. I chalked it up to being really really bad with a belt grinder and/or poor design.
 
Cynic2701 said:
I once saw a cheap Chinese copy of a higonokami (sp?) knife. The blade had 5 bevels. I chalked it up to being really really bad with a belt grinder and/or poor design.
Click to expand...

I think I was guilty of that, the first time I tried to freehand sharpen. :D
 
I just want to say thanks again for all the great input here, I am in agreement with a lot of what was said. Thanks especially to knifenut for leading off with a very complete response and the links that helped out. There are definitely a lot of terms having more than one meaning when it comes to sharpening. I have read some info on the topic and what makes the most sense to me is as follows. Of course cbwx34 said it very well that you have to understand the context and find out what makes sense to you. Anyways, this is it from my point of view.

Blade grind - This is the first grind encountered moving from the spine of the blade towards the edge. This is the general cross sectional shape of the blade in terms of flat grinds, hollow grinds, convex grinds etc...

Bevel - Basically any place on the blade where steel has been removed to create some type of slope. By this definition clearly the edge bevel and micro bevel are included but also the blade grind as well.

Primary bevel - Synonymous with the blade grind. When moving spine to edge this is the first grind encountered. Again this is the general cross sectional shape of the blade. This is the first grind in shaping the blade and therefore I think makes sense to be called primary.

Secondary bevel - This is the second bevel encountered going from spine to edge on the blade. This also may be the first part of the edge bevel (depending on how you define the edge bevel). The secondary bevel can continue to the very apex of the edge if there is no tertiary bevel.

Tertiary bevel - This is the third bevel encountered going from spine to edge on the blade. This may be the second part of the edge bevel (depending on how you define the edge bevel). In either case, the tertiary bevel forms the apex of the edge.

Micro bevel - Synonymous with the tertiary bevel.

Shoulder - A transition point from one bevel to another. Couldn't have said this one any better than knifenut's definition.

Back bevel - Synonymous with the secondary bevel on blades that also have a micro bevel (at least that's what my sharpmaker tells me). This is the bevel that backs up your micro bevel and therefore gives it more strength.

Edge bevel - Truly could have many meanings like a lot of these terms. Basically the bevel that forms the apex of the edge (therefore could be the primary, secondary or tertiary bevel) OR could be a combination of bevels such as secondary and tertiary that together comprise the edge of the blade. In any case, the grind making up the apex of the edge is included in the edge bevel.

here are a couple more...

Blade profile - This is the shape of the blade as viewed from the side. This is the blade shape in terms of drop points, clip points, tantos etc...

Blade geometry - The composition of the grinds of the knife including the primary, secondary and tertiary bevels. This is a representation of the blade that takes into account all the grind angles making up each bevel.

There are many schools of thought as far as how these terms are used. After doing some reading this is the way I tend to agree with, but that's just my way of looking at it. Let me know what you guys think, or if any of that was confusing or anything. Again, I really appreciate the response. Thanks everyone.
 
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Seems like you have a handle on it, now if you could just get every knifemaker, sharpener, critic, user, etc to follow the same set of definitions I think it would be a success!

But you're right, you need to know what is being referred to in order to determine its usage in context.


-Xander
 
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