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Make a hot cut hardy


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That one wasn't my idea. Alfred Habermann had me make him 2 to take to Japan with him so he could cut down on weight. It actually seems to be more stable than most standard hardy tools and easier to fit. I don't see any reason that you couldn't adapt it to other hardy tools, but I have never made any other hardy tools like that.

Nothing compares to the other hot cuts in the first picture for stability, but I would not use the tapered shank for other hardy tools used for forging because you might brake your heel off.

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That one wasn't my idea. Alfred Habermann had me make him 2 to take to Japan with him so he could cut down on weight. It actually seems to be more stable than most standard hardy tools and easier to fit. I don't see any reason that you couldn't adapt it to other hardy tools, but I have never made any other hardy tools like that.

Nothing compares to the other hot cuts in the first picture for stability, but I would not use the tapered shank for other hardy tools used for forging because you might brake your heel off.


Brian, why would a tapered shank cause the heel to break? Thanks for the ideas. Edited by ofafeather
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Brian, why would a tapered shank cause the heel to brake? Thanks for the ideas.


Ofafeather,

To jump in before a response from Brian comes. If you look at the taper shaft hardy, you can see that the blade part does not settle against the face of the anvil. I used one of the hot cuts a couple of weeks ago and I can say that it sticks well above. If you use the taper on a fuller or swage, you would be pushing the taper in too far. This could cause the heel to break from the pressure along a line at the hardy or at least make it very difficult to remover the bottom tool. Having a taper isn't the problem, it is the size of the shaft at face level. If you taper the shaft so it is at the max size of you hardy at face level and the rest of the tool sits against you anvil face then you should be fine.

Hope that makes sense... of course I can always stand to be corrected.

Brian
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Well, actually, when you're cutting hot metal with a hot cut hardy, the metal is being cut not forged, and it yeilds much easier. Notice the difference over time between the struck end of a top hot cut and a top fuller. The fuller will have much more mushrooming occurring and a flatter will have even more and a hot cut will have barely any. It has to do with surface area contact and the way that metal yeilds more easily to smaller surfaces. I would not use a tapered shank that sticks up above your hardy hole with forging dies, but it is fine with a hot cut. I have never broken any anvil with these hot cut hardies, and I've used them in all kinds and sizes of anvils, even with full blows from a striker. I can cut 2" tool steel in one heat with these hardies by myself with a hand hammer, and I know I couldn't do that with a hardy that jumps or moves.

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Well, Brian Pierson nailed that. I think that style hardy is great, but I find with what I manufacture, it has to fit peoples perception of what that tool should look like. I even get complaints if I put too much (in their opinion) crown in the cutting edge.


I was typing that last message when you replied to the previous.

I know what you mean, but I'll just say to the other smiths out there that, "I don't know who came up with a staight hot cut hardy, but I'm sure it was not a blacksmith! Blacksmiths do not use straight chisels."
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Blacksmiths do not use straight chisels."


I've run into this before but haven't found good explanation of it. Is the curved chisel to make chasing a line easier, improve (or reduce) chip load on the tool edge, prevent the tool from jamming? All of the above and then some?

Phil
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Try chopping with an axe that is sharpened straight across.


Yeah, but with an axe doesn't that have to do with the pendulum aspect of the stroke? Carpenter's axes and splitting axes tend to be straight across. Gransofr Bruks Carpenter's Axe When someone starts swinging the hot cut hardy, it's time to leave. :o

Why are curved chisels/hardies better if they aren't being swung?
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It has to do with surface area contact. The smaller the surface area contact, the more penetration or movement of the metal you get. If you lay a flat piece of metal across a flat or straight chisel, top or bottom, it will tend to bounce back and not penetrate as much as a crowned chisel would. And if you rotate your material and create a smaller surface area, instead of plowwing through in the same position, you will get more penetration and protect your hardy from excessive heat especially with larger cross sections.

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That's interesting. The other effect would be to create more of a slicing (shearing) cut which should be easier. The highest point of the crown is the only part that's chopping.. All of the other parts are entering at an angle to the material and are slicing. I'm not at all experience in metalworking but I know from woodworking that when you skew a bladed tool (even a straight bladed to) you get a slicing cut instead of a chopping cut which is usually cleaner, especially on end grain. Also the resistance drops dramatically. The few hardies I have seen in my vast experience (I've been to one hammer-in :( ) have all been straight.

Would you do the same for cold chisels, too?

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I don't do much cold chiseling. I use my hot cuts to score bars sometimes, and then break them.
Alfred Haberman would cut plate with a hot cut cold using cutting oil, and those were definately crowned.
I did cut a 1/4" thick bar 4"x 6' a while back and did one side cold and the other side hot to see witch would be better. I liked the cold side better, and it was quicker. I used a hot cut that was crowned, and I used oil.

19583.attach

19584.attach

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I've run into this before but haven't found good explanation of it. Is the curved chisel to make chasing a line easier, improve (or reduce) chip load on the tool edge, prevent the tool from jamming? All of the above and then some?

Phil


The curved edge on a chisel gives more control in use, you can easily locate it to start, and then use a rocking motion from the initial mark to easily develop a longer cut in the direction you want, (correcting as you go if necessary) and you can also use it to cut around curves.

This also applies to hot sets and hardies to a degree.
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Things don't have to be complicated. I use an old hatchet head in a small bench vise for my hot cut. Works very very well. I don't have an anvil. No hardy hole, just have to make do with what I have. Piece of rail screwed to a stump to hit hot iron on, my vise hot cut, channel locks and vise grips for tongs. 3 small but functioning tongs I've made, (ugly buggers). Just keep hammeren on.

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Brian, that's really interesting. Thanks for sharing. Can you tell me about your table? That looks really handy.


That is not my table. That is Tony Swatton's table.
That is a typical platten table, sometimes referred to as an Acorn table, and they are really handy. They can be found out there, but they are a bit heavy to carry around.
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  • 4 weeks later...

A really interesting thread,
I will obviously have to grind a curve on my hot cut that I made form a wood splitting wedge (as I didn't have an axle laying around) - cut and forged the shaft - a bit tall but works for me - now out to the grinder to make it better.
Trevor

post-4049-12623921673071_thumb.jpg

post-4049-12623921860825_thumb.jpg

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That is not my table. That is Tony Swatton's table.

That is a typical platten table, sometimes referred to as an Acorn table, and they are really handy. They can be found out there, but they are a bit heavy to carry around.

Around here they are called "Layout Tables"..There is one about 1 mile from that is 10 feet x 8 feet ...They wont sell it to me though..I do have standing dibs on it when they do..
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My thoughts on this, What and how much are ya cutting. 5 Pieces of 1/4 round or 2 pieces of 1/2 a day or a week
Probably woun't require a hard tool. (We are talking HOT iron here) If your doing a lot of cutting harder would be better. I made 2 bought 1 don't use them much at all.
Ken

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Chucking in my 2 cents ( and that's about what it's worth), there is a point to be made with forging your own tools. When I first started, I almost never forged what I could buy. More recently (the past 5 years or so), I have started forging more of my own tools, and my skill level increased dramatically. In my opinion, it is because I have to forge to a specific dimension and shape. When I do the pretty stuff if I am off by a bit I can usually tweak it to make it work. With tooling, if I don't make it the right size/shape it doesnt work or it takes a lot of work to correct it. Therefore I take a lot more care with the forging process to make it come out right. In turn, this has made all my pretty stuff come out a lot nicer as my skill level increases. The more I practice forging to specifc dimensions the better I become. Maybe someday my skill will be as good as I want it to be.
Mark Emig

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Since I've moved around quite a bit and had a number of temporary homes, I've used all kinds of "yee haw engineered" setups. One time in Central America, charcoal was cheap and plentiful but the only anvil I could manage was a big ol chunk of basalt rock. It was harder than the back of my head and had one sharp edge where I could hot cut steel. I've also used pieces of sharpened leaf spring driven into the end of a stump.

Just for fun, have a look at this smithy in Africa. Pay particular attention to the "hand crank blower" behind the forger. Then be grateful for your own setup.

http://www.youtube.c...h?v=nQMkWHrt-i0

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