The oldest new question in knife making

[Pontif]

OK, this question has been kicked around so much that many will probably not even mess with it. However, having so little experience with carbon steel (I make all my blades with ATS, S30V, BG42, etc via stock removal), and virtually no experience with forging, will the masters of the "flame" chime in on why the carbon blade (forged or not) appears so superior to the stainless blade in performance. At the same time, would those utilizing stainless for their blades give me their reasons.

I understand the chemistry, carbon migration, etc. What I am looking for are examples of the difference in practical application between the basic forms of steel.

I am a huge fan of Fowler. He uses 52100 and has extremely good results with the steel and the manner in which he heat treats it. Also, the forging process appears to make a significant difference in the performance of a blade. He wrote a specific two part article in Blade Magazine that compared two knives that were exactly the same in form and steel, but one was made via stock removal and the other was made via forging. I never found the second or follow up magazine. He did indicate the two knives performed quite differently.

What are your preferences (re. steel) in a survival blade? Why? And, if possible, give an example of how the particular steel, heat treatment process, forging or stock removal, etc., played a part in the steel's performance (or lack of, if applicable).

Thanks for addressing this one - AGAIN - for a newbie to your group.

Pontif

 

[JShirley]

why the carbon blade (forged or not) appears so superior to the stainless blade in performance

I do not believe anyone could fairly say that old-school carbon blades are clearly superior to newer rust-resistant steel alloys. Even 52100 has over 1% chromium, though in my experience, it does still rust easily. Cliff Stamp has a good steel summary page here.

Welcome to THR.

John

 

[Pontif]

Thanks John. I knew this question was a bit of a mouth full. I appreciate the link.

P

 

[hso]

The heat and beat boys will tell you that grain alignment and refinement during the forging process results in better performance in a forged blade over a stock reduced blade. M'be.

 

[pbearperry]

I wish there were more old carbon steel knives out there to buy.Stainless is pretty,but I find putting a good edge on them problomatic.

 

[The Tourist]

Stainless is pretty,but I find putting a good edge on them problomatic.

Pontif, this statement is one of the most common misconceptions you're about to run into. It happens everytime a process comes along that takes that part of the industry to new ground.

For example, my fellow Harley riders are lamenting the loss of their carburetors. However, you should see my latest dyno run. And as we speak, "direct injection" is on the horizon. Some folks just don't want change.

As for steels like BG-42 and S30V, I had a never ending line of guys who claimed to be boners in the old Madison Oscar Mayer plant. "Nothing will beat a butcher's carbon steel knife for sharpness," they would say. Then I would hand them a S30V blade right off the stone.

Some alloys require a mirror finish, and S30V is one of them. It responses very well to Japanese waterstones and polishing paper and buffing tapes.

We simply need different tools to get the better results.

 

[pbearperry]

It's not a misconception to me,I just can't sharpen stainless as easy as carbon steel.It may just be that I have no proper training in this chore?Plus I really love Damascus looking blades.lol

 

[The Tourist]

I have no proper training in this chore?

Get hold of my friend and mentor Mr. Ben Dale over at The Edge Pro.

www.edgeproinc.com

For the home, they have a machine called "The Apex" which will help a home hobbyist keep his personal stuff very sharp.

I have two of the other model, "The Pro." I carry one in my truck for seeing clients at their job sites, and one at home for folks who drop stuff off.

It's not the "be all, end all." Once you start getting stuff spooky sharp you find yourself buying pastes, papers, new stones, glass mounts, fairy dust and just about everything advertised as "Japanese in origin." You curse yourself for all those wasted years chasing women when you could have gone to classes in actually reading Japanese...

I belief swarf is a seductive drug...

 

[Pontif]

Thanks for the input, guys.

I look at the typical tests that have been used to test the edge retention of different blades. I know that blade geometry and edge bevel are all factors. In fact, there are so many different variables that you can throw in that the question I have asked may be invalid.

BUT!

Fowler used a 52100 steel, forged, dif heat treated, et. al. - and was able to make a reported 450+ cuts on a 1/2" (I think) hemp rope. They stopped there because of lack of rope. The best that I have been able to get from an ATS34 blade (heat and cryo treated to RC60) is just over 80 before it started to tear rather than cut.

I have even gone so far as to try to edge pack stainless, and once (and never again, I still have a bad shoulder from it) I actually gave my best at cold forging prior to final finishing of the blade. Damn, that was a long ordeal.

I need more experience with S30V and certainly 3V (3V - Hitachi super alloy - they call it). I just hate the cost. Screw up on large survival blade, or even a moderately sized boot knife, and you can be out a chunk. Goes with the learning process, however.

Any input on the super alloys? Good ole D2 or O1? I hope to be a BONIFIED knife maker when I grow up.

 

[Dr. Tad Hussein Winslow]

Tourist, thanks very much for that link to edge pro - those contraptions are EXACTLY what I've been looking for, for a number of years now.

 

[dagger dog]

If I may add,

The sharpness of the stainless, is not really a factor, it can be sharpened to an edge as sharp as high carbon no doubt, but the edge is too hard and crumbles upon hard use, that has always been MY big problem with stainless.

High carbon water hardening tool steels forged and properly tempered, are eaiser to keep an edge mantained, and is not so prone to crumbling. I have found that the razor type hollow ground blade honed to a thinner cutting edge is easier to push through muscle, cartilage, sinew, and if the stainless is sharpened to that same degree of angle that permits the same ease of cutting ,is very prone to the edge crumbling.

Some may say not to use such a low angle, to reduce this negative effect, but if done, results in greater force being needed to push the blade through said material.


Seasoned or green wood and other similar material may be a different story.
But as for weapon material or butchering I believe high carbon forged is the way to go.

 

[The Tourist]

High carbon water hardening tool steels forged and properly tempered, are eaiser to keep an edge mantained, and is not so prone to crumbling.

That's news to both me and Paul Bos. The secret is the heat-treat, and many cutlers are manufacturing tools and knives from stainless that make carbon steel say 'uncle.'

In fact, Graham Brothers Knives makes their Razel (a knife part chisel in design) out of S30V, a stainless alloy supposedly easy to chip.

The whole matter is simply "time goes on." My wife has a knife made from CPM-440V. Yes, it chips. However, it's about eight years old.

And let's give credit where credit is due. Paul Bos can heat treat a gum wrapper and then drive it through body armor. And to be sure, cryo quenches are now more common place.

Now, D2 is one of my favorite steels, however, the knife that I have already been bangin' around--and will ride with me this summer--is crafted from S30V. So are both of the Striders I own, and Mick would never let a blade out of his shop that he knew would one day fail.

And of course, not every step forward is truly a benefit. I'm not sure this high RC stuff called ZDP-189 is really going to help the consumer.

 

[dagger dog]

TT,
I'm not talking about structural failure of the blade ,but to the microscopic wire edge that makes up the fine black line that is visible to the naked eye.

Once that has crumbled the blade is no longer sharp. As in razor sharp, or that thumbspliting sharpness. The carbon blade you simply strop it across the palm of your hand or your leather belt and that edge which on a carbon blade is just turned over ,stands back up and the sharpness comes back, but on the harder stainless chromium alloy blade that edge falls off, and the razor edge is gone. Thats the edge I'm refering to.

The harder stainless types( my laymans term for the newer steels),have their use , as a matter of fact, I own a Cold Steel Tanto the 11" more or less . You could drive that thing through a 1/8" steel plate with a sledge hammer and would still have enough edge to cut through leather gloves and most of your hand if handled right. But it wouldn't shave you.

There are different uses for a blade , and for most the eaisest to maintain are carbon steels. I wouldn't think of piercing steel plate with my skinning knife it would probably ruin it. But under the usage it was intended for, I can strop it and shes ready to go again! Razor sharp.

 

[The Tourist]

wire edge...crumbled the blade is no longer sharp

Hmmm. I know what you mean, but I don't want to give you an answer and sound like a "guru."

I use waterstones, pastes, papers and glaziers glass to best offer a rendition of a system with one foot in 13th century Japan. I consider the theory and the application to be better than traditional methods most American folks know and use.

A working "tinker" who uses these methods and tools first starts off with stones finer than we here normally use. This "tinker" also uses many stones, and carefully steps to finer and finer gradations to remove both tool marks and those microscopic 'fingers' and edges.

In many ways, that just repairs the edge. You must remember, to the Japanese, a sharpener is actually a "polisher."

Using pastes on very fine paper (and I mean out to 6000 grit fine), the tinker mounts this combination on the most perfect and structurally strong surface he can. We used to call this "glaziers glass." (We now refer to this as 'thick glass.') It's a kind of extremely perfect glass with no air bubbles or grit, and it is very clear. I believe old lenses were made from this, like those in a lighthouse.

Several papers are then used, each finer. At this point, there is no working wire edge, to the touch or the eye. But a "good tinker" will apply fresh paste to a clean paper and adjust his hold slightly "up on the edge."

Some people call this a "micro edge."

In any event, the knife is flipped side to side, buffed and examined. It is then returned to the client, along with six bandages and a pint of plasma.

Now, my knives are like this, professional chefs have knives like this. I owed a favor to Don Hayes and I did a neck knife for him. Obviously it's expensive. On an expensive Japanese laminate "the tinker" gets 15 to 20 dollars per inch.

However, if you are having trouble with a knife prone to these problems, my guess is that a pro should examine the angle, repair the knife and buff the edge.

A knife that fails is no investment or use, anyhow.