How sharpen tamahawk

[jbtusa]

There are a few chips on the edge of my tamahawk. Problem is that my bastard and mill files won't touch the edge because it is too hard. The hawk has not been sharpened before so the original meat of the edge is still there, however deep that might be.

So I will have to use an electric side grinder to sharpen it. My question is how far back can I sharpen the edge before I grind through and past the hardened steel?

 

[swedepie]

Don't know cause I don't have one. It's not very traditional, but I have sharpened axes with a belt sander and it works very well. Put axe in vise and run belt away from edge. After you get it shaped up and sharp to your satisfaction, then take a stone to it and finish up. Mac.

 

[ohio ramrod]

If files won't cut it. Angle grinders or belt sanders will. The question is: is the whole head hard or just a case hardening on the edge? Case hardning is only on the surface but if the whole head is hard you can grind and grind and grind.

 

[Mad Professor]

Are the files from Walmart/China?

If the edge is harder than a good file it's way too brittle

 

[Many Klatch]

If you use a grinder or a sander remember to keep the metal cool so you don't take the temper out.

If the hawk is used for competition throwing, I like to have a really flat angle on the grind. I have been to events where the hawk block was fresh cut and hawks ground like an axe would bounce off. A really thin ground blade would stick in.

Many Klatch

 

[R Jones]

jb, I use a 220 grit belt for the initial grind. A spray bottle of water can be used to keep it cool. Finish with a 400 grit belt for a razor edge. :wink:

 

[LRB]

If this is a blacksmith forged head, chances are the edge is forge welding in like a sandwich. The edge steel can go up the head from a couple of inches, to all the way. At any rate, it is a tad bit too hard. If you know the maker, contact him and tell him, although I know a few makers who use 52100 steel for the edges, and they often run them pretty hard. Even so, it really does not need to be that hard. Since a file will not cut it, that indicates that the edge is harder than 58Rc. An axe, depending on the steel, does not need more than a hardness in the low fifties, and many are in the forties. If you could find out what the edge steel is, it would a simple matter of re-tempering in your kitchen range. You could do that anyway, if you wanted to experiment. Temper for an hour, starting out at 425°. Check it with a file. If still too hard for the file to cut, go up 25°, and try again, and so on until you can cut it with a file, then you will probably have want you want. Use an oven thermometer. Do not trust the range setting.

 

[jbtusa]

Here's a photo of the hawk. It looks like the hardened blade is quite deep and that there is little risk of grinding through the hardened steel.

 

[ohio ramrod]

If you try tempering in the oven remember to remove the handle first!

 

[paulvallandigham]

That hard steel insert is between 3/4" and 1 " from the edge back. You can see the slight depression where the two thinned sides of softer iron/steel were opened to receive the thicker hard steel insert. That is still a lot of steel to worry about grinding or sanding through. It looks like an H & B Forge hawk. I have one from them that looks very similar to the one pictured here.

You need to use either a sanding wheel, or belt sander, or fine grind stone to cut a more shallow angled bevel back from the edge. Go for a bevel that measures between 30 and 45 degrees, but no more. On bigger axes, some go as high as a 60 degree bevel, but generally such a wide angle is used on wedges and splitting mawls for light work. Heavy splitting is down with a bevel of 90 degrees, for splitting stumps. For green wood, as mentioned above, I have put a 22 degree bevel on my axe, just to get it to actually stick in the green end grain! I don't like to have to do that, as the edge can be more easily damaged with such a shallow bevel. Rather than take the chance of ruining a good tool, I will bow out of competitions where I think there is a better than even chance that my axe's edge will be damaged by participating. It may because of how the backstop is constructed, or the fact that the backstop is placed over stones, or concrete pads. It just takes too much effort to put a fine edge on a shallow bevel blade to risk damaging it. If I find that staples are being used to tack playing cards to the stump for targets, I will not throw my axe at the target or backstop. That tiny piece of metal can take a divot out of the edge of any axe I know, considering how much energy is behind throwing it at a target. I have seen dull axes survive hitting staples, and drive them deep into the stump's endgrain. But that just makes matters worse, to my way of thinking.

 

[Twice boom]

First of all like it's been said the edge angle is too steap for an ax . Secondly no one has mentioned it but If I were to take the chips out of the cutting edge the way I would do it is by first grinding the cutting edge blunt far enough up until the chips were removed. Next I would regrind the cutting edge to have less slope .Then polish the cutting area two inches up from the edge. Heat the oven to 450-500 degrees place in the oven for 30 minutes ,then start watching for tempering colors . Purple is what I would want or something close to it. Take it out of the oven quench in hot water .Then put back in the oven for fifteen minutes then quench once more.
After the last quench I would finish the job by stoning the edge to my satisfaction,or use a file first depending on the thickness of the cutting edge after taking the chips out, than stone to a finish..

 

[LRB]

If the steel happened to be 5160, that could be a tad too much heat if at 500°. Not saying it would be useless, but maybe softer than wanted. Since the steel type is unknown, I would think it safer to start out at a lower temp and see what you get. One can always re-temper at a higher degree, but you can't go back once done without a complete re-HT.

 

[Twice boom]

You could be right about not knowing the type of Steel used. Having said that, we do know one thing, the steel used was able to take hardness to a point where the cutting edge chips,light purple will be just fine in my opinion..

Straw color will leave him with but one option,the grinding wheel or the belt sander when time again to sharpen,if not chip the blade again...IMO.