Tempering Cast Brass At Home??

[satx78247]

Friends,

How do I go about tempering a cast brass "trade" tomahawk head's cutting edge, so that it can be sharpened with a file/stone?
(I "googled" it and found essentially NOTHING except a pair of "highly technical" documents that frankly I didn't understand. - I'm not a metallurgist.)

yours, satx

 

[jdkerstetter]

Hardening and tempering with heat are techniques used on iron-based alloys/ferrous metals, they don't really work on brass/bronze, as far as I know.

It should be soft enough to file as is as most brass is soft enough, even harder bronze can be filed....provided your file is new and sharp. Once a file has been used on steel it can be all but useless for filing brass.

But brass, being soft, won't hold the edge when used to strike harder objects. Fine as a weapon for striking soft flesh, practically useless as a utility tool.

Brass will work harden if you beat on it repeatedly, but too much it becomes brittle and will crack or break. It can be annealed or softened by heating it to dull red and letting it cool naturally or quenching it in water.

Many will dovetail a steel bit into the leading edge of their hawks, but they are still more for looks than utility.

Enjoy, J.D.

 

[necchi]

JD got it,
" It can be annealed or softened by heating it to dull red and letting it cool naturally "

This is from Center fire loading techniques, brass cases get brittle and have to be annealed.
Brass is just opposite of steel and it's the heating that softens the brass. (aligns the matrix)
You can quench it also as it makes no difference.

Dull red is all you want, advice is to wait till dark or go into a closed room with no light, and using a propane/map torch slowly bring just the edge up to a very dull red and stop.

Trouble usually comes from an unknown alloy. Brass is copper and zinc,, but many times there's other stuff in there too especially with the imported cast items, you just don't know what's all in the metal.

So with the above said, I'd just do a small corner of the blade,, and test it before I did the entire piece. Heating can and will lead to a blue edge where the temp change occurs, that can be polished off if the brass is actually brass.

But that's how you anneal brass.

 

[Len Graves]

As was said before, annealing is a softening process. This is done by heating to a dull red color, which was mentioned. If your hawk head is all brass it should be easily filed without annealing it ,I think softening it would defeat your purpose. Most brass hawks were for ceremonial or decorative purposes Any way.

 

[LRB]

The only way to harden brass is to work harden it. If your edge is thick, you could hammer it some, but I think any gains you might get will be so insignificant as to consider the process as a waste of time.

 

[satx78247]

THANKS, Gents.

Fwiw, the casting foundry rep told me that the raw casting of their tomahawk heads need to be "buffered & tempered" before sharpening.
(I've never really worked with brass before.)

Btw, some very old tomahawks at our Tribal Office show "considerable use" and were evidently used in war, so they weren't all just "ceremonial objects" or "novelties".

yours, satx

 

[LRB]

I have no idea of what that rep meant by "buffered and tempered". You can look up the properties of brass yourself. It cannot be heat treated to be harder than it is. In the cast condition, it should be as hard as it can get, without hammering the edge, which at some point will make it brittle. Used in battle, possibly so. Used as a cutting tool, folly. The condition of those old tomahawks you mentioned could be from many causes other than battle. Children playing with them for one. Careless abuse for another. Doesn't take much to scar up brass.

 

[satx78247]

Wicke Ellerbe,

I presume that the sole thing that those old tomahawks ever used for "cutting" was human flesh.
(Tsalagi warriors were once, quite rightly, feared by the tribe's enemies. = As late as WWII, both Germans & Japanese soldiers found out that our warriors "haven't lost a step" over the olden days, when it comes to "hit and run" warfare.)

The reason that I asked the question of our membership is that I had NO idea what "the rep" meant by "buffered and tempered" & I've not been able to contact him since. - Sounds like to me that he has "a head full of rocks".

THANKS for your comments.

yours, satx

 

[Wes/Tex]

Like the others, I didn't think you could actually harden brass. Most of the original brass headed tomahawks I've seen had a narrow iron or steel edge and the brass sides were hammered along the leading edge of the blade. You might try heating and quenching a brass head but I'm not certain it'll toughen up enough to be sharpened.

 

[LRB]

It won't. It will soften it.

 

[dikman]

"buffered and tempered"? Sounds to me like that rep doesn't really know what he's talking about.

(I've never come across the word "buffered" being used with regard to cutting tools ).

 

[LRB]

During the Bronze Age, it was discovered that bronze tools and weapon edges could be hardened by hammering and shaping in the cold condition. The same can be done with iron/steel, but is only beneficial when the carbon content is too low to harden well by heat and quench. Some believe this process is the origin of the "myth" of "edge packing" steel blade edges, that is still used by some blade smiths today. With bronze, brass, and steel, the resulting hardness and, in the case of steel, grain refinement, is nullified by red heat.

 

[satx78247]

Wicke Ellerbe,

THANKS for your comments.

yours, satx