Re heat treat old half hatchet?

[Cleave]

So I got this old half hatchet recently. It is marked "R. King Cast Steel Made in United States."
A quick wire wheel de-rust, flatten the back a bit, new handle from a honey locust tree. Then filed the bevel. It filed very easily, too easily. Sharpened it up a bit on the stone, and tried it out. The edge rolled over pretty easily confirming my suspicions that the steel is too soft.

Now, I've done a bit of blacksmithing recently (still a total newbie), and am wondering if it is worth pulling off the handle and re-heat treating this? Anyone have experience with this? I'd bring just the blade edge up to non-magnetic heat, then try oil quench first, then water quench if it didn't harden enough. Then temper it in the oven (I have a great wife). I suppose since the tool doesn't hold an edge well now, there's really nothing to loose if I'm careful and don't burn it up.

 

[ThomasPowers]

Is that a hewing hatchet, bevel only on one side, or a felling hatchet bevels on both sides.

If you want to use it I'd try heat treating, much the way you mentioned save that I might go with brine if oil didn't work.

[Cleave]

Yes the other side is flat for hewing beams.

I have no real reason to keep tools that don't get used.

Also, should I normalize 3x before heat treat or take it straight to heat treat?

[ThomasPowers]

Don't know that without you telling us---Al foil hat must be working.  Did you flip the blade around when rehafting?  And if so did the eye support that? (Bevel side up to the left in first picture and bevel side up to the right in the second picture.) Some eyes have an even hourglass and others have a biased hourglass.

Anyway go for it!  

[anvil]

I would normalize once, anneal, harden, temper.

[JHCC]

1 hour ago, Cleave said:

should I normalize 3x before heat treat or take it straight to heat treat?

Normalization IS a kind of heat treatment; I assume you mean "harden and temper", yes?

Annealing wouldn't be necessary, as you don't need it dead soft for filing or grinding. You might want to do the triple normalization (bring to critical, air-cool, repeat) to ensure that the grain size is good (annealing can increase the grain size, and therefore should not be done after normalizing), then harden and temper.

 

[Steve Sells]

First off normalizing before annealing is a waste of time , and second, I agree the annealing is not a good idea.  If you do anneal you will need to normalize a few times afterward to reduce grain sizes. I would just normalize, harden then temper

[JHCC]

Ah, Steve agrees with me. A lousy week just got a little better.

[Buzzkill]

In the past I've been involved with a couple discussions where one person was referring to a subcritical annealing and another was referring to an intercritical annealing.  While both of those are intended to soften the steel and relieve internal stress, my understanding is that the effect on the crystal structure and grain size of the steel is different.  I'm not sure if this is another case where that confusion comes into play, but it's possible.

[Cleave]

By normalize, I meant bring just above critical and let air cool, back in the fire 5 or 10 minutes later, repeat 3x, to stabilize grain structure before quench.

The eye did look even, so could be hung either way. The thing is very symmetric, maybe you could even run a wedgeless handle, with a snug tight fit, and flip it around as needed to access tight spots. That way a carpenter only needs to carry/purchase one.

I successfully drilled out the wedge and removed the handle without destroying it and plan to try heat treating again when I get a chance. 

Thanks all for the counsel and entertainment.

[Steve Shimanek]

Just to bring another view to the table; perhaps the temper is a bit soft on purpose to allow the user to easily touch up the blade while working? Geometry of the edge is important; if the edge was thinned excessively, the edge might roll. Food for thought.

[anvil]

You didnt say where you got it. A flea market? Antique store? No matter, it has no edge holding ability. Perhaps it went thru a fire.

Im not a collector of tools, so the name means little to me.

I would assume, for starters that the steel is a high carbon steel and do a complete heat treat. I would also do a spark test to see if the pattern matches any of my known samples.

I'd follow the sequence given in many places such as the heat treaters guide and for a half dozen steels listed in Cashen's site amonst a few other sources. I listed that sequence above. Works well for me.

[BIGGUNDOCTOR]

I wouldn't heat the whole thing, just the front edge back a couple of inches or so. Less fuel, less chance of making the back brittle, less coolant needed to quench, and the back can be used to run the colors for tempering.

[G-son]

Many axes (and other cutting tools) have mainly been made of cheaper low carbon steel, with just a small piece of high carbon steel forge welded in for the cutting edge. You may have an axe that has been used and sharpened so much the edge steel is gone, and what remains will not take a heat treat. A new piece of suitable steel can be forge welded to it in that case, used to be a common repair.

[ThomasPowers]

And in that particular case an "inverse cleft weld" (body to  HC is -> rather than <- )or a lap weld are easier than the cleft weld it might have started with.

Chisel edges were often lap welded HC on the "bottom" so there would always be HC at the edge until it was all worn away.  I have a commercially made adze that has a quite thin pad of HC welded on the bottom so the chisel edge will always be HC.

[BIGGUNDOCTOR]

G-son, he says it is marked Cast Steel

[ThomasPowers]

Right, short term memory is not what???

[JHCC]

Loss of memory is one of the three warning signs of impending senility. I can't remember the other two.

[ThomasPowers]

Being fussy about grammar?

[Cleave]

Right, I wondered about if the blade was forge welded HC and is gone now. And figured that "cast stee" meant the whole thing was likely the same alloy.

Maybe it got in a fire and killed the heat treatment? Or somebody went nuts on it with a grinder at some point? Anyway, the edge rolls a burr within a few minutes of use. May as well try the re heat treat and learn something. It was raining yesterday so didn't light my campfire forge.

[G-son]

3 hours ago, BIGGUNDOCTOR said:

G-son, he says it is marked Cast Steel

I believe that relates to how the steel was made, not that the actual axe is a casting. In itself it doesn't seem to confirm or deny that the axe is a welded or monosteel item - everybody in history has bragged about the best properties of the items they sell, I have so far not seen anyone try to sell cutting tools saying "we make them with the best steel for the cutting edge and the cheapest stuff we can get away with for the rest". You mention the good stuff, you don't mention the rest...

Either way, a simple spark test should give you a good idea if you've got high carbon steel or not. Take it to the grinder and the sparks will let you know.

[ThomasPowers]

Cast steel was generally much more expensive and so really only worth it for items needing HC.  It was teemed in fairly small ingots that were then forged to the needed shapes. I don't recall any references to using it for cast mild steel items.   (Steelmaking Before Bessemer: vol 2 Crucible Steel" goes into greater detail.)

[Cleave]

Well, my hasty side got the better of me.

I got the campfire forge going, heated the blade side to a red, checked on the magnet, let it cool for maybe 10 minutes.

Put back in, heated blade side a bit hotter (to make sure the whole way across the blade was hot enough).

For some reason, I went straight for the water quench as I only have about a gallon of used motor oil and a #10 can on hand........

Got some warm water in the 5 gallon bucket, and quenched, held her in there and stirred it around for a while. There were a couple ominous pops.

A file couldn't touch the edge.

My gracious wife didn't complain while I tempered it in the oven at a bit over 500 F, got a nice blue color on it.

Then I noticed, twin cracks halfway through the sides of the eye one on each side. Should have heeded better wisdom and quenched in oil first! Or maybe don't hold it in the water so long, or don't heat up that hot. Not sure which it is. But still, a good experiment and learning experience.

Now.... I have access to the father in law's welder but am pretty new to that myself... would it be a good idea to grind a v groove on the cracks, preheat, and weld the cracks back, then re heat treat??? Really this is just for the learning experience at this point.

[ThomasPowers]

Why was the section that did not need to be hardened that hot? I would have suggested only the edge be heated for hardening.

[Cleave]

With the campfire forge, I don't know if I'm capable of getting the heat that localized. Or perhaps the forge can do it and I haven't figured out how yet.