cast or forged heads...

D

deserthawk

Joined
Nov 19, 2005
Messages
70
been thinking lately about differences in cast vs. forged hawk heads...
any difference performance wise? i tend more towards a hand forged head, for it has some spirit of the maker, some slight hammermarks, even if it was made by a low wage sweatshop worker in a third world country. i prefer American made first choice. but hey ya throw what ya get...

anyone have preferences, comments?

dhawk
 
Its not an absolute or even a perfect analogy . Take a mold like a hawk head . Put wet sand in it . Heck I,ll even let you pat it a bit so as to make it more interesting . Now take that same wet sand put it in that same form and pat it down hard . After that take a press the size of the form and really hammer on the top of it . That sand will pack down and squeeze out any of the tiny air pockets that are sure to exist . Now look at both hawk heads . The patted one is a crumbly edged mess and the pounded one at least keeps its form enough to show you what it was .\
Transfer this idea to metal hawk heads and of course it is not a perfect analogy . A lot more goes on inside a forged hawk head than ever happened to pounded sand .The cast head is just that, molten metal poured into a form .A forged head while having many variants, for the sake of this discussion is pounded into shape , the metal being compressed or work hardened if you prefer . If you just want to look at it on a physical level refer back to the pounded sand . It holds its shape better because there is a tighter physical bond inside the structure . Of course inside the hawk head this change is done on a molecular level . I don,t think we need delve that deep to understand the principle .
Like I said there are no absolutes . I betcha there are some cast hawks that are made well . People are darn smart . I know there are forged hawks that are just no good cause people can be pretty darn lazy too .
I asked a question on hawk forging that shows an inexpensive way to make a good forged hawk . I think it is the way that my townsend Light infantry hawk is made. I like it for two reasons . It shows it is really well made for the money and it shows a way they have been making forged hawks for centuries .
 
Hand forged or drop forged are better than cast. It defintely has to do with molecular structure and the temps that are used. Cast heads tend to be wall hangers because they're more brittle as most cast manufacturers will tell you that cast heads are not made for hard use or throwing.

When you forge a piece of metal, the high pressures "collapses" the individual grains. The result is a little denser, and will tend to bend rather than break. It can be a lot stronger than a casting, or the same shape cut out of a flat lump of metal. The surface, since it took the highest loads will often be the strongest, and the less you can disturb this surface, the tougher the part. A break may actualy show a fairly shiny surface, as the space between the "grains" is gone. The direction of flow as the metal is squeezed imparts a grain structure to the metal that is a bit like that of wood, making it substantially stronger in specific directions. Well-designed forging tools and dies control this flow so as to make the part strongest in the directions it is expected to be stressed in.

Casting is the forming of metal parts by pouring molten metal or other material into a mould. This is the cheapest way of making large quantities of parts that are of shapes that cannot be produced by stamping. The parts are not generally as stong as those that can be made by forging.

Suzanne Settle
Owner
Bear Mountain Tomahawks
www.bmtomahawks.com
 
Suzanne,

Is Bear Mtn Tomahawks a new development or am I just terribly out of the loop?
Regardless, congratulation!


Deserthawk,

There exists a 3rd option for tomahawk manufacturing. Some of the ATC hawks are machined (cut) from blanks (billets?) of modern tool steels. I've never heard of one of those failing.


Later,
B.



NorthStarXO said:
Hand forged or drop forged are better than cast. It defintely has to do with molecular structure and the temps that are used. Cast heads tend to be wall hangers because they're more brittle as most cast manufacturers will tell you that cast heads are not made for hard use or throwing.

When you forge a piece of metal, the high pressures "collapses" the individual grains. The result is a little denser, and will tend to bend rather than break. It can be a lot stronger than a casting, or the same shape cut out of a flat lump of metal. The surface, since it took the highest loads will often be the strongest, and the less you can disturb this surface, the tougher the part. A break may actualy show a fairly shiny surface, as the space between the "grains" is gone. The direction of flow as the metal is squeezed imparts a grain structure to the metal that is a bit like that of wood, making it substantially stronger in specific directions. Well-designed forging tools and dies control this flow so as to make the part strongest in the directions it is expected to be stressed in.

Casting is the forming of metal parts by pouring molten metal or other material into a mould. This is the cheapest way of making large quantities of parts that are of shapes that cannot be produced by stamping. The parts are not generally as stong as those that can be made by forging.

Suzanne Settle
Owner
Bear Mountain Tomahawks
www.bmtomahawks.com
Click to expand...
 
thanks for some technical clarification, i needed that.

Suzanne, (or others)... with knives the type of steel used is always an imortant point and of course that goes hand in hand with the Rc rating. i can't recall ever seeing any of that info in hawk ads. occasionally you will see one saying something like "brass head with hardened steel insert", but that really tells you nothing. or some third world foreign companies with their marvelous mystery metals of the week. i have seen some hawks i am sure was made from parts of Peugot engine block, lol... thanks all...

dhawk
 
Greetings,
Personally I like forged heads, because of the time and effort spent to make a good tool (ok, so I am a bladesmith) but I have thrown some nice cast ones as well.
I would like to bring up a few points on the subject of density...A cast piece may have voids or air pockets in the metal that will be weak spots, and therefore slightly less dense, but forging does not cause the steel to become denser. even the 100 ton steam hammer in PA cannot forge a piece of steel and cause it to become denser. there is no room in a block of steel for the atoms to compress.
What you want to look for is a nice fine grain pattern, but forging alone cannot do that. for forging to reduce the grain size you must reduce the cross section by 40% or more. Those old timers that say how great edge packing is don't realize that the hammering dosen't do the work, the heat does. bringing a piece of steel to critical temperature(about the point that it becomes non-magnetic ~1550 deg) and then letting it air cool to 800 deg or so, the grains reform into smaller grains, and a smoother matrix.

With all of that said the real difference, what matters the most is the heat treatment. you can do everything right, screw up the heat treat, and get a piece that is nothing but a wall hanger.
 
I am not a metallurgist, neither a knife maker, so please excuse my ignorance.
Is it possible that forging (+ heat treatment) changes the microstructure in specific areas while the overall, average density of the steel remains the same?
 
yes, that is the general idea, any work done to a piece of steel, may change the grain structure in that area, for better or worse. if care is taken to watch heat and not to forge too cold, the maker can produce a superior blade.
 
I have a couple of cast cutting tool's a double bit hatchet and a tomahawk both are made by 2Hawks I got the Trapper Double Bit Hatchet and the Warbeast none are wall hangers and I use them in the bush so far I have nothing but praise for them, I don't abuse them but I do use them hard, towards the end of last winter I took my double bit hatchet out sometimes just for a hit cup of coffee on the open fire and we had a cold winter here in Ohio and it preformed great it was like a lightweight that punches like a heavyweight I plan on using it in warmer weather too I like to go lite in tge summer, but I also got a Warbeast now that's a chopper the three edges really help extracting the Hawk out of the wood and it bites deep too I like it on longer trios because it can be taken apart for other applications like a Ulu or to scrap, a wedge etc, and more portable to just pack it and there are numerous new ways of carrying hawks now anyways since they are becoming more popular, mine are cast but when I'm chopping with them they feel very Solis and hold a great edge mine are also made out of 6150 and have a high RC so I believe they were tempered good and so far so good.
 
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