Quality of steel : forged vs. stock removal

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krept

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Jan 14, 2002
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How does a finished forged blade made of 5160, etc. compare to a blade created using stock removal from a bar of D2 or 1095 vs. 154CM, etc?

This is, of course, assuming equally high quality heat treatments that bring the most out of each blade.

I believe that I have read that the process of forging a blade creates a superior product, but then again I am wondering if this information was in light of the new wundersteels available from Crucible, etc.

Are forged blades tougher? Are the stock-removal blades more uniform in composition? Is there even a significant difference between both finished products?

Sorry if this sounds incoherent, I just came out of a looong meeting.
 
The major difference is that there are fewer things to go wrong with the stock removal process, ie carbon burnout, forged in inclusions etc but I must say that there is a certain mystique and appeal in a handforged blade.
 
I prefer to forge blades to grinding them out. To me, its a hell of a lot more fun. That is the primary reason I forge. I do not believe that just because a blade is hit with a hammer makes it better than a ground out one. Like Mr. Tichbourne said, there is less to go wrong with a stock removal blade and I fully agree having made knives both ways. Also, I have to add several more steps to my forged blades than I did for my ground blades.

-Jason
 
I haven't started forging yet,but to the advantage of having a blade close to the finished product and not spending as much time at the grinder is of a great benefit. You also have the ability of buying a greater range of material to start with (round stock etc.) Also you can start making damascus!
 
I view this as a "which is better" sort of question and to be perfectly honest, there is not a right answer to this. It all depends on where YOU want to go. Explore!

C Wilkins
 
Reason I started forging was because I cimply couldn't afford steel.

But broken leaf-springs... how much do ya want? I loaded a car trunk full twice of a series of mercedes leafsprings, from a certain year, a certain milling run, but they were all 1 inch too long to fit the new trucks :D so i have a bunch of excactly the same 5160 (i had it checked) springs, kinda like 600 pounds for excactly 0 bucks (ok, the gas for driving up and down 5 miles twice).

Sooo.. I make a knife, from a steel which costed me excactly say 1 $, let's compare it to say ATS-34 which costs like 30 $ a foot. Does ATS offer 30 x the performance of a 5160 blade? I think it'll be good HT'ed ATS if it passed the 1 mark. Now if you go for hi-tech CPM metals (talonite including) OK, they are great cutters, but in a price - quality evaluation they simply cannot come close to 5160.

That is all speaking for everyday carry knives... there are some specialty knives (military, diving, fishing.. ) which do demand extreme performance, which 5160 might not be able to provide due to lack of stain resistance, then it is sensible to use super alloys.

Choosing a steel is based on several factors (toughness, edgeholding, ease of working, flexability, forgivingness... ) but everyone forgets price. If you take in account price, you know why forged blades are far superior to stockremovalled blades. OK, they can stain... but by god.. they will cut for a LOOOOONG time. Ever heard anyone complain about Ed Fowlers 52100? Some super alloys, at 10 x the price, can't come close to that level of edgeholding.

OK, so why forging ? the repeated heating and mechanical deformation kinda breaks down grain structure of steel. 52100 benefits greatly from being forged, same as with 5160. Forging also has another advantage.. if you can forge it, you can also Heat-treath it yourself, which means higher level of commitement of the maker to the blade. Some maker out there could be replaced by a CNC machine-park. They create incredibely nice knives, but they could have been created by a machine as well. A forged blade cannot be made by a machine, and it kinda lets you know too when you hold it.

Soo with some steels it is actually better for the steel to be forged, to get the same level of performance from a stockremovalled blade you'll need to lay down way more cash, More commitement of the maker and the possibility of damascus... Need more reasons why forged blades are superior?
I fogot the best one.. it's way more fun :D

greetz and take care, Bart.
 
Forging is fun,And I prefer to not just take a pattern off the wqll and cut it out...
Carbon versus stainless is that you can differentially heat treat carbon but not stainless.
Basically it is what ever your customer wants,or what you prefer to do..
Forging lets you use inexpensive scrap material to make blades from instead of putting out allot of money on new bar stock also..
Sorry I can't give any better answer..
Bruce
 
I don't think it makes sense to compare forged 5160 and stock removed D2, ATS34. It would be better to compare forged 5160 with stock removed 5160. Assuming heat-treating for both is optimium, I don't think there is any difference. Of course this is my non-expert opinon.

While I'm far from a metallurgist, I just don't understand how hitting steel improves it. All steel are forged, at the factory. You can't make it any denser. Hammering the steel may or may not help the crystalline structure, but wouldn't the subsequent heat-treat nullify that work?

I think one area people don't think about much is that smiths by nature know more about heat-treating than a stock grinder since he does his himself. The smith has more control over what's going on, but as someone pointed out more can go wrong too. That may account for whatever difference there is in performance.

In any case, swinging a hammer all day is definately healthier than being blasted with metal dust.
 
In my book 5160 that is forged makes a beter knife
than a stock removel knife. The more you forge 5160
the better it gets, a finer grain a much better
knife. Ed Fowler has done a lot of resurch on this.
Gib
 
Well you have gotten a lot of good answers but the one I expected hasn't come up yet. Imagine making a knife from a straight grained board. If you cut it (grind the shape) the grain runs out.
Now imagine making a knife from a board that forms the shape of the knife itself. The grain follows the contours of the knife.

Which one do you think is stronger for the same weight?
 
Wow, good replies is right. I'm becoming more interested in forging and I haven't even finished my first knife via stock removal.


Tallwingedgoat makes a good point. But why wouldn't you be able to forge D2? Is the melting temperature too high?

It just seems like so much research goes into these steels that they have to be technically more sound. Then again, so much human energy goes into a forged blade that has to be something special.

The fact that they are handmade makes them all the better, IMO.
 
this debate will go on till hell freeze's over.:) as has been stated it depends what you end use will be. also bruce, you can diff, heat treat stainless. i have done it with ats-34 with decent results, and paul bos did it until the E.P.A. shut it down.
 
Laurence,I didn't know that could be done :o ..Sorry for the mis info there..Do you get a hardened line from it when it is defferentially heat treated like this ?
How do you do it ? and can it be done in a gas forge?
Guess I should only answer on the carbon steel since I haven't worked much stainless :o Sorry..
Bruce
 
Years ago Wayne and I did an experiment contrasting stock removal vrs. forged blades. The results are on page 105 in my book "Knife Talk". The forged blade multiple quench out cut the stock removal blade also multiple quench by over twice. The blades were from the same billet of steel and the test was extensive. There is as much difference in forged blades by different makers as there are different steels and methods. We have found ways to push the stock removal blades, but also improved the forged blades. The most significant difference as usual is the dediction, knowledge and commitment of the maker on each individual blade.
 
You are on the right path tallwingedgoat, keep it up. :cool: As for the wooden board idea. I understand what you are talking about peter, but you are playing with several variables here:

For one, this "grain" you speak of runs into a few areas. If you are speaking of the actual grain itself and talking about simple steels like carbon steels and alloy steels, the grain can be made quite homogenous. The grain can be recrystallized through normalizing or some other form of annealing. This eliminates significant directional properties, if not all (when done right). After forging of any kind, if you do not run some sort of anneal, you will be leaving the steel in a random grain orientation when it cools from both the hammering and the heats. Cold working for example... with a material like mild steel, if you roll it cold, you can stretch the actual grains and distort them in the direction you roll it in. Annealing will fix this.

However, in a steel like D2 with its larger carbide concentrations, the carbides get smeared out into "fibers", "stringers" or "bands". This property will definitely create noticeable directional strengths. Thus, a "grain" effect like wood takes place. Such an effect is not eliminated through traditional annealing techniques, despite effective recrystallization of grains. Martensitic stainless steels also suffer from this. REAL wrought iron is a great example of this effect, except you are dealing with ferrous silicate slag and other impurities instead of carbides. The effect is similar. This is why Crucible has gone to such pains to create their CPM products. The carbides are too small to get smeared in rolling them out. The carbides remain evenly distributed in all areas. Ala, no banding. Many carbon and low alloy steels (likely eutectoid and under mostly) form little to no banding. Since they do not form large clusters of carbides (segregation within the ingot prior to forging), there is no need to produce such steels through particle metallurgy techniques like CPM. Forging a CPM product is another story and kind of negates the whole process unless you REALLY know what you are doing. You may get fusion of carbide in the hand forging operation. Okay aaaaaanyway, back to the point.

Forging DOES effect grain size, both in its hammering and in its heats, but this concept must be understood. Such effects ARE negated for the most part, through proper annealing/normalizing and even the hardening in some respects. This is a topic within itself. Again though and I must emphasize, even with a steel like 5160, a stock removal maker can match the perfomance (grain too) of an identically forged version if he understands the steel and how it works. I am unsure of the effects hammering will have on banded steels. In some cases, it may help, such as cross rolling a steel in the mill. Another debate though.

Phew. I'm exhausted. :cool:

-Jason
 
bruce, i did not get a temper line from diff, treating ats-34. i took it to cherry red with a propane torch in some fire bricks and quenched in 150 degree atf. then did the file test. i dont have a exact R.C. but after tempering by taking the spine to blue, they cut and held fine. mr. bos can of course give a more inforative awnser to this process. the best piece of advise was from mr.fowler who told me me that the only rule in knifemaking is to have fun!:)
 
Theories abound concerning the properties of steel. You can find theories that defeat or support your goals as a knife maker. The ony method of progress is to develop a comprehensive comparison testing system to examine the variables in reference to puropse. Tough, cut, strength are all easily tested in the shop of the bladesmith. Develop your blades in accord with purpose, then examine the theories to explain where you have been and you will find it makes sense. Otherwise you will run in the treadmill and realise no progress.
 
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