How much does "forged" mean?

Shing

Shing

Joined
Feb 2, 2003
Messages
2,261
Some knives are made by forging a piece of round bar or a piece of metal several time thicker than the finished blade while others forge a blade out of a piece of flat steel approximately the same thickness as the final blade and only the edge and point is forged.

The amount of forging in the former is obviously a lot more than the latter. Is there a difference between the two in terms of performance?
 
Last edited:
Welcome to the forum.
No difference, what matters is the steel, end result and final heat treatment weather it was forged from round bar, flat stock, or was made entirely by stock removal.
 
"Jesus Christ can send a bar of steel down from Heaven. It will only be as good as the heat treatment it gets on Earth."
Jerry Rados

Add to that an old blacksmith saying that "when forging, we have far more opportunities to ruin a perfectly good piece of steel than we do opportunities to improve it."

Both of those illustrate that the final quality of a knife is determined by the expertise of the maker - not the steel or how it was shaped.

But now that I think of it - what is the question?

If you hit it with a hammer and change its shape - it is forged.
Is it improved as a result, or perform better than a knife that is not forged? That's all in the heat treatment. But there are those that also consider the forging one step of the heat treatment. So, it all depends upon the maker.
 
Last edited:
I've been wondering too whether forging could produce an improvement in steel properties, and I believe it could, but I'd welcome opinions on whether my reasoning has any merit. 'Moving' the steel with hammer seems to me as similar to hot or cold rolling the steel, as is done in mills. From an engineering point of view, steel can be thought to have same properties in every direction (orthotropic material), but it rarely is: it is a well documented fact that rolled steel will exhibit different strength in three principal directions (highest strength is in direction it was drawn and lowest in the direction steel was compressed, which is the plate thickness). If I was to speculate as to why that happens- I would guess that internal stresses in the material resulting from grain deformation will oppose or increase external loads (just like is done with shot peening)... And I don't think subsequent heat treatment would change that tendency, although it might slightly diminish it.
 
With 5160 and 52100 (jury's still out on 80CrV2) i personally like the results I get from forged blades rather than stock removal. This should by no means be regarded as gospel-historically (for me) they just "run better". Could very well be geometry and balance, but until that changes I'll continue to work those steels the way I do.
The big advantage of forging (to me) is the plasticity of the material-to make a blade with a 3" curve I don't have to buy a 3" wide bar, I can just forge in the curvature (only one example).
Bottom line is a well HT'd blade is a well HT'd blade.
 
Every piece of steel you get has been forged.

When all forging procedures and thermal-cycling have been done correctly, there is no difference. If you are getting better results from forging, it just means you are missing something when you're doing stock removal only. If you are getting better results when you stock remove, it is because you are not forging properly.
 
Don- really?!? ;) I hope my comment wasn't considered in the same vein- my reasoning was based on the fact that THE (I'd say most highly thought of, and most recommended) aircraft design handbook speaks of the subject, specifically in which 'orientation' are high stressed parts to be cut from rolled material, and that serious materials handbooks (like DoD aircraft materials handbook) list properties in different directions for rolled material. I've attached properties listed for AISI 301 SS. Maybe I was wrong in *ass*uming the 'moving' of material when forging might be similar in effect (it works on similar principle as rolling), but I don't think it's that far-fetched. :o

 
Time tells all ! In the 'old days' steel quality was such as to benefit by forging.Today with higher quality [lower non-metallic inclusions ] it's really not going to matter much.
 
I may be wrong, but I do believe that is to avoid the "directionality" of alloying/carbide bands in cast steel. From what I have been told by some in the steel biz, you avoid that in some cases by rolling in multiple directions. The specific example given was rolling sheets for making big industrial circular saw blades.
Wolf_HR said:
Don- really?!? ;) I hope my comment wasn't considered in the same vein- my reasoning was based on the fact that THE (I'd say most highly thought of, and most recommended) aircraft design handbook speaks of the subject, specifically in which 'orientation' are high stressed parts to be cut from rolled material, and that serious materials handbooks (like DoD aircraft materials handbook) list properties in different directions for rolled material. I've attached properties listed for AISI 301 SS. Maybe I was wrong in *ass*uming the 'moving' of material when forging might be similar in effect (it works on similar principle as rolling), but I don't think it's that far-fetched. :o

Click to expand...
 
Shing said:
.... Is there a difference between the two in terms of performance?
Click to expand...

There is little or no difference in the steel, however, forging a blade provides additional means of shaping the blade and the resulting product can be enhanced by a good design that takes advantage of that.

n2s
 
Wolf,
When you are talking about the stresses on a forged aircraft landing gear I'm sure that forging the direction of the landing gear would improve things.
On the level of a knife I doubt there is notable difference in forged or stock removal. This is sounding like the Baked or fried bacon thread in W & C:p

Wolf_HR said:
Don- really?!? ;) I hope my comment wasn't considered in the same vein- my reasoning was based on the fact that THE (I'd say most highly thought of, and most recommended) aircraft design handbook speaks of the subject, specifically in which 'orientation' are high stressed parts to be cut from rolled material, and that serious materials handbooks (like DoD aircraft materials handbook) list properties in different directions for rolled material. I've attached properties listed for AISI 301 SS. Maybe I was wrong in *ass*uming the 'moving' of material when forging might be similar in effect (it works on similar principle as rolling), but I don't think it's that far-fetched. :o

Click to expand...
 
Silly rabbit, edge packing only works when you quench in virgin/unicorn blood.

My belief is that forging is there to create shapes that would be otherwise too difficult to create with stock removal, such as integrated bolsters, san-mai, damascus. Likewise, less material is wasted when forged by someone who knows what they are doing.
 
I've been thinking about this as well. As long as you are transparent in your process I think anything goes buy using forged ad a sales point and just flattering the metal with a power hammer and then sawing and grinding the flat forged bar to shape. I don't know about that. I mean if you think that the word forged ads value it's a bit of thrickery if there really has been no bladesmithing done. I might be wrong but that's just what I was thinking a week a go or so looking on some knife maker homepages.

Edit: There was no thrickery on the pages I looked at but it got me thinking. :)
 
In all seriousness a "Hand Forged" knife is better.....for the maker...as he can charge more, and the public will pay it.

There is no metallurgical benefit beyond the material size needed for a knife.

It has great cache' in selling. Many makers mark their forged blades "hand Forged".
 
If you start with a good steel. Made by a good company. Don't stress or warp it. Heat treat propperly. You should get a good knife reguardless of drop forge, hammer forge or stock removel. Now a master might be able to yeld different results between his process. But he would be able to prove these claims if so.
 
What wolf says is true but not relevant for knife makers as the stock is too thin. At least that's what Kevin Cashen has on his site. Go there to check it out if you want more info.

Regarding forging the abs taught me to finish the knife to about 80% or better at the forge. It does save money on things like belts as there's less to grind away and it gives you that tie to our ancestry that didn't have fancy belt grinders. As others stated you can do things like integral guards and such which would be difficult without forging.
 
if present, any kind of misplaced anisotrophy on a bar of steel is not gonna resolved by forging a knife out of it with hammer and anvil.
Take a glob of playdoh, blend random strings of another color playdoh and start hammering....see what happens.
 
You must log in or register to reply here.
Back
Top