How long should a razor edge last

Blues Bender said:
Wow, I didn't mean to sound so vague in my post to op. I just didn't want to take up 2.5 pages of this thread talking about metallurgy:D

I understand that there is no distinction/definition of "hard or soft" steel, but in the instance of op's "why is s30v better at holding an edge that a noname/sak steel" I think its safe to say s30v can be called "harder" and will hold an edge longer than said steels (not all). S30V is harder to sharpen than something like sak steel because it is harder and more resilient.

I dont claim to be an expert, but I didnt think op wanted a scientific explanation:p
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Well the SAK Steel is in the 55 range and I have personally seen S30V in that same RC range.....

So both steels in the same RC range and S30V will still hold an edge better..... ;)

That why we went off, because it's way too vague to be even close to being remotely accurate.....

I do understand making things easier to understand, but that was/is really vague.....

Vague enough that anyone who knows what they are talking about would go.... HUH? WHAT?

Sometimes we just can't dumb things down THAT far..... And still make since or be accurate....

That's like telling someone man my car is fast, I put gas in it and it goes.......... HUH?.......

S30V holding an edge longer than the other steels has less to do with RC hardness and more to do with Alloy content/Carbide content.... Same with being somewhat harder to sharpen, it's more wear resistant than those other steels due to the Carbide content.
 
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Ankerson said:
S30V holding an edge longer than the other steels has less to do with RC hardness and more to do with Alloy content/Carbide content.... Same with being somewhat harder to sharpen, it's more wear resistant than those other steels due to the Carbide content.
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Excellent, brief, concise response. Gotta say one needs to really know his stuff, as you do, to pull off an answer like that one.
 
Folderguy said:
So tell me please, Ankerson, do you have a doctorate or advanced degree in metallurgy?
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No, it's more a lot of experience over the years, reading books, and speaking with those who really do know what they are talking about. :)
 
Ankerson said:
Well the SAK Steel is in the 55 range and I have personally seen S30V in that same RC range.....

So both steels in the same RC range and S30V will still hold an edge better..... ;)

That why we went off, because it's way too vague to be even close to being remotely accurate.....

I do understand making things easier to understand, but that was/is really vague.....

Vague enough that anyone who knows what they are talking about would go.... HUH? WHAT?

Sometimes we just can't dumb things down THAT far..... And still make since or be accurate....

That's like telling someone man my car is fast, I put gas in it and it goes.......... HUH?.......

S30V holding an edge longer than the other steels has less to do with RC hardness and more to do with Alloy content/Carbide content.... Same with being somewhat harder to sharpen, it's more wear resistant than those other steels due to the Carbide content.
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You make some good points, but I was under the impression that vanadium carbides are strong/harder than a sak steel which presumably has no added vanadium (thus making one harder than the other). Like you said, regardless of rc, the s30v is made to hold an edge better due to more than one factor.
 
Blues Bender said:
You make some good points, but I was under the impression that vanadium carbides are strong/harder than a sak steel which presumably has no added vanadium (thus making one harder than the other). Like you said, regardless of rc, the s30v is made to hold an edge better due to more than one factor.
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Oh, they are, the carbides are harder themselves, not so much the steel...

Think of it like concrete with rocks in it, the rocks are harder than the concrete.

Vanadium carbides are harder than ANY steel....
 
Ankerson said:
Think of it like concrete with rocks in it, the rocks are harder than the concrete.
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That's a very good explanation, I never looked at it like that!

I always looked at steels as a "blend" rather than a "homogenous matrix of elements".

Learn something new everyday;)
 
There is soft and hard in the non-technical world of the Average Joe

They know nothing about metals and steels,
Except the blade is soft when it is easy to sharpen and gets blunt fast
And a blade is hard when it is difficult to sharpen and stays sharp

We might be intellgent and understand what he means is infact a composite of complex issues
And transalate this in to his view
But no amount of technical insistance here will change a common man's simple and accurate perception
 
neeman said:
There is soft and hard in the non-technical world of the Average Joe

They know nothing about metals and steels,
Except the blade is soft when it is easy to sharpen and gets blunt fast
And a blade is hard when it is difficult to sharpen and stays sharp

We might be intellgent and understand what he means is infact a composite of complex issues
And transalate this in to his view
But no amount of technical insistance here will change a common man's simple and accurate perception
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And then there's tailoring the edge finish and geometry to meet the job (or bulk of the job) that any given tool is intended to do, and combine that with the qualities of the steel. Have come to a working concept of edge dulling that tries to use the edge finish requiring the least amount of pressure to do a given task. If a rougher finish and a drawing action will cut a given material with less applied force than a bright polish and a pressure cut, that edge will likely last longer. Conversely if a bright polish and a pressure cut will sever/part a given material with less applied force than a rough edge drawn, that edge will last longer (all other things being equal).

Most of the time I just go with a medium high finish because its the fastest and easiest to touch up with a minimum of removed steel, with the tools I prefer for maintaining an edge. Not necessarily the best finish for all jobs, but everything is a trade off.

Another thought, I have done no controlled testing, but would swear some of my high RC carbon steels hold a fine edge as long or longer than my examples of s30v or D2.

Ultimately the answer to how long a razor edge should last might best be "however long it lasts". If it doesn't hold up as long as you'd like, make some changes to the maintenance interval, geometry and/or edge finish.
 
Ankerson said:
EXACTLY......

And we are back to the original question.... :D

WTF is a hard or soft steel.....?

And were in the hell are they getting that terminology from?
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You seem to understand metallurgy better than you understand English. The original question was not "wtf is a hard steel."
and while it may not be the only factor in edge retention, hardness is a factor, so to talk as though it isn't is rather misleading, don't you think?
 
neeman said:
There is soft and hard in the non-technical world of the Average Joe

They know nothing about metals and steels,
Except the blade is soft when it is easy to sharpen and gets blunt fast
And a blade is hard when it is difficult to sharpen and stays sharp

We might be intellgent and understand what he means is infact a composite of complex issues
And transalate this in to his view
But no amount of technical insistance here will change a common man's simple and accurate perception
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Perception can be a powerful thing....

However it's usually wrong in the end... No matter how much someone believes it to be true.

Like in the example you stated.....

I can completely reverse their perception of what a hard and soft steel is just by changing the edge geometry and edge finish...... Using the same knife they are holding at the time.
 
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W.M.B. said:
You seem to understand metallurgy better than you understand English. The original question was not "wtf is a hard steel."
and while it may not be the only factor in edge retention, hardness is a factor, so to talk as though it isn't is rather misleading, don't you think?
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Guess you didn't read the whole thread.....

Like the parts when I pointed out they aren't referencing actual RC hardness when they say hard and soft steels....

Or this post that I made.....

Ankerson said:
There are a lot of factors that are involved in edge retention.

  1. Alloy content/Carbide percentage
  2. Edge geometry
  3. Blade Geometry
  4. Edge finish
  5. RC Hardness/Compression strength of the steel

Compression strength is directly related to RC hardness and since edge dull mostly due to blunting, rolling etc so the higher the RC is the longer the edge will go before it starts to deform so the edge will stay sharper longer compared to the the same steel at a lower RC hardness.

Wear resistance is important and is directly related to alloy content/Carbide content so that will have an effect mostly on more abrasive materials being cut.

Blade and Edge geometry are important because the thinner the blade is and the lower the edge angles are the easier it will move through the media being cut. Now if we get too thin for the use at hand the reverse will happen and the edge will dull too fast so a balance has to be met. Too high RC hardness and the edge will chip out too early and dull too fast.
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Ankerson said:
Guess you didn't read the whole thread.....

Like the parts when I pointed out they aren't referencing actual RC hardness when they say hard and soft steels....

Or this post that I made.....
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I did in fact read the whole post, including the original question. Did you?
The original question was "how long should a razor edge last?"
I suppose my best answer would be, it depends on the blade, as well as how you use it.
Not real technical, perhaps not real satisfying. I'm sorry, but that is the best answer I can give to the original question.
 
W.M.B. said:
I did in fact read the whole post, including the original question. Did you?
The original question was "how long should a razor edge last?"
I suppose my best answer would be, it depends on the blade, as well as how you use it.
Not real technical, perhaps not real satisfying. I'm sorry, but that is the best answer I can give to the original question.
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Yeah, after reading the 1st 5 posts I made #6......

The answer really isn't THAT simple, and I wanted to find out what people thought a hard and or soft steel is as I have seen the terms used lately in different places as they were here.....
 
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Ankerson said:
Yeah, after reading the 1st 5 posts I made #6......

The answer really isn't THAT simple, and I wanted to find out what people thought a hard and or soft steel is as I have seen the terms used lately in different places as they were here.....
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So how is it you did not know what the original question was?
And as to my admittedly simple answer,
Does it not depend both on the blade in question, and also how it is used?
 
W.M.B. said:
So how is it you did not know what the original question was?
And as to my admittedly simple answer,
Does it not depend both on the blade in question, and also how it is used?
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Along with a lot of other factors that can effect the outcome....

Nothing is that simple... :D
 
Ankerson said:
Along with a lot of other factors that can effect the outcome....

Nothing is that simple... :D
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The question was simple, so i figure the answer should be too. I think you are trying to substitute some other related questions for the original.
 
W.M.B. said:
The question was simple, so i figure the answer should be too. I think you are trying to substitute some other related questions for the original.
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The question is simple, the answer however isn't as it's complex.
 
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