Thanks, I was in two minds whether to grind it all off originally, but I ended up just flattening the tips of the teeth and keeping the pattern.I like that a lotvery nice, the file bit just adds something to the look of the blade .
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pedrobedro
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I always like file knives, how did you soften the file for grinding ? I'm looking for an old file or rasp that isn't case hardened like the modern stuff, pity the farrier across the road passed away 
I haven't done any knife stuff for a couple of years now, probably longer I can't fit everything into my busy schedule being retired 
Sheaths are something I'd like to get better at as well.
I haven't done any knife stuff for a couple of years now, probably longer I can't fit everything into my busy schedule being retired Sheaths are something I'd like to get better at as well. 
It's made from an old Nicolson file, hard all the way through. You don't need to anneal for grinding or drilling. For grinding a Zirconium linishing belt will remove metal quickly, aluminium oxide a bit slower. For drilling use carbide drills - the one I used is a re-ground masonary drill, don't let it get too hot or the braize will melt and the carbide fall off. I also ground a starting point for the drill with a Dremel prior to drilling.
DAPPH
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Usually the old stamped (Made in India " files are cast steel. then hardened & tempered.I always like file knives, how did you soften the file for grinding ? I'm looking for an old file or rasp that isn't case hardened like the modern stuff, pity the farrier across the road passed away
View attachment 364528 View attachment 364529
Hot Pony Shoes may have old farriers rasps if you ask him nicely.
It's 56 years ago that I did a month's workshop processes & materials intigrated in with a months daily blacksmithing in the forge and on the anvil during my 3yr apprenticeship , manage to do a wee bit since but none in the last 15 years ...here's how I recall things in my dotage.
You only need to heat to bright cherry red , reach yellow or bright orange or white and you'll likely burn the steel, once it loses colour to just over dark cherry red reheat, Forge to rough shape, then normalize the forged blade in the air , drill your scales fixing holes at this stage ... no quenching ,
Clean the still hot metal with a bit of carborundum stone or emery cloth ( take care..... it'll be hot ) till you see bright metal,
Harden to iridescent purple , on a red-hot block of iron or steel , remove from heat & by now it will have blued . quench in warm water.
Warmed water It's all old-fashioned blacksmiths had, though history says some Arab & Chinese sword makers used to cool their blades in body of a sacrificed slave (cheaper than warmed water? )
This blue colour means it's about as hard & brittle as it can become , drop it on a hard floor & it's liable to break .
Now it's hard .hot & blued, clean off the bluing with the carborundum or emery cloth to get sight of a bright metal , now put it back on the red hot block to get it light straw colour run fromthe back of the blade to the front edge along the width of the blade , then quench in warm water to stop it losing the tempering. Tempering removed the brittleness, so you end up with a hardness that's not brittle
Hone & polish on a whetstone if you can so you don't ruin the tempering. Burnishing to a shine is possible and difficult as you usually need some very fine India stone.
None of this forged in fire crap of shoving it in quenching oil and hoping its's OK ,
Look around carboot sales & garage sales as well as on eBay ,they'll usually have a squared tang or a wooden handle
DAPPH
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outofthefire
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Good luck with that, heat treating could turn it into a nightmare, it wants to be something thin and springy
Different steels can need heating to specific temperatures, your method is a good rule of thumb if you can't tell the temp and you're not sure of the material. But I would never quench a thin edge in water. I heat treat hammers, axes and chisels daily and while I either heat them with a torch or induction heater thin profiles can easily crack in water, you might get away with it, but if you've spent ages working on a knife it's not worth the risk.
slim_boy_fat
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....pity the farrier across the road passed away
I have a couple of farrier's rasps, one could be yours if you cover postage?
Screwdriver
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Sorry to disagree but if you do not heat a hardenable steel past its curie point (at least) prior to quenching, it will not harden. If you have forged a blade and allow it to cool, it will form a massive crystal grain structure internally (also the wrong sort of crystalline structure) and be soft + weak. All you will accomplish by taking that to a "nominal" annealing temper temperature (like the "spring blue" you describe) is effectively low temperature normalising.
Forged in fire is perhaps a little bit overstaged but the hardening process they show is correct. Interestingly, they never show the annealing process because I once read somewhere al the compeditors items were annealed by their own in house technicians. I seem to recall Walter Sorrells moaning about that after they broke his katana...
pedrobedro
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Thanks for the offer slim but we get them in the tool box at the local second hand shop so I'll pick one up there when it's more likely to happen. If I get one now it will be lost by the time I get round to doing anything with it
h-dom
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Do you mean tempering rather than annealing?Sorry to disagree but if you do not heat a hardenable steel past its curie point (at least) prior to quenching, it will not harden. If you have forged a blade and allow it to cool, it will form a massive crystal grain structure internally (also the wrong sort of crystalline structure) and be soft + weak. All you will accomplish by taking that to a "nominal" annealing temper temperature (like the "spring blue" you describe) is effectively low temperature normalising.
Forged in fire is perhaps a little bit overstaged but the hardening process they show is correct. Interestingly, they never show the annealing process because I once read somewhere al the compeditors items were annealed by their own in house technicians. I seem to recall Walter Sorrells moaning about that after they broke his katana...
The best way (for me) is to cut two slithers off and test quench them, one in oil and one in water. If it hardens in oil, use that. Stick them in the vice and hammer it to break it. If it bends, it's not hard, if it breaks, it's hard. Look at the grain. If it's nice and fine then all good.
I don't do so many knives any more but I do make a lot of smithing tools for myself. I generally just quench them in the oil and get on with it, but I get that with a thin knife it's more involved.
Normalise three times before quenching, up to orange and air cool until you're able to pick it up.
pedrobedro
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The procedure I read with old files or rasps was to leave them in a fire overnight to anneal them so they could be worked with a file then after working heat and quench then temper to make them less brittle. That was on the old British Blades website before it went.
Screwdriver
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I am referring to the process as described in the post I responded to where the steel is never hardened because @DAPPH was suggesting (incorrectly) that you do not need to quench from "red hot".
Under those specific circumstances, taking a piece of unharderned steel (because I suggest it will not be hardened) and then only take it "up to the blue annealing temperature" will do nothing except possibly normalise the steel and potentially allow an even bigger grain structure to develop!
Like you I will generally get the thing red hot, non-magnetic and dunk it in old chip fat. Smells great.
But once the subject strays into the science of the process, I am all over it. Many various techniques will work but there are two issues when generalising:1. A specific grade of steel, O1, W1, 1095, 4140 etc. will have its own well known and well documented heating and tempering process.
2. A non specific mystery metal is more "suck it and see.
I have found that rebar, files, farriers rasps actually do harden well in water. I agree 100% with @outofthefire that water quenching is fraught, especially with thin blades and forge welded composite structures (san mai, damascus pattern, chisels with forge welded tips). Then you're literally asking for splits and warps but with homogenous single structure materials like leaf spring, rebar, files, water will get the thing glass hard no doubt about it! There is of course a much higher possibility of destruction but hey, that's why you're using rebar, leaf spring etc. anyway....
h-dom
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I meant when talking about forged in fire...I am referring to the process as described in the post I responded to where the steel is never hardened because @DAPPH was suggesting (incorrectly) that you do not need to quench from "red hot".
Under those specific circumstances, taking a piece of unharderned steel (because I suggest it will not be hardened) and then only take it "up to the blue annealing temperature" will do nothing except possibly normalise the steel and potentially allow an even bigger grain structure to develop!
Like you I will generally get the thing red hot, non-magnetic and dunk it in old chip fat. Smells great.
But I do agree with everything else, but I always thought taking it up to blue was just a spring temper, if anything it will make it softer. I take stuff to blue if I need to drill it etc.
Normalising then will bring the grain structure back down and then quenching will harden, but only from a red non magnetic heat.
Screwdriver
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It was this part I object to where you suggest “forge to shape, normalise, no quenching”
Normalising allows the part to relax into shape but also the slow cooling promotes grain growth. It HAS to be brought back up to red or orange heat/hardening temperature to allow the crystalline structure to reorient itself into a different arrangement, and being obstructed by the presence of alloying elements (carbon atoms etc), you want to literally freeze that structure into place ASAP.
After the quench, the material is so cold, the iron lattice cannot shift around or reorient itself, it gets stuck in a super glassy hard condition. You can then ease that hardness back slightly at the much lower annealing temperatures for which this universe has miraculously provided a handy colour chart.
The annealing temperature allows a much lower level of diffusion activity within the lattice. My understanding is that while annealing, the crystal grain boundaries can shift around slightly in the highly stressed areas which had been frozen in place, drawing back the “temper”, slightly softening the material to stop it being so brittle. It’s all about grain size…
Due to the strict order of operations required (the structure will change differently at a given temperature depending on whether you’re heating it up or cooling it down) it is vitally important to harden first, then temper.
outofthefire
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At work we hardly ever temper anything, hammers, axes and stone masons cold chisels. They all in effect get an edge quench, they're heated up to a colour usually just passed red then allowed to cool to blood red then quenched in either oil or water. The face or edge is the required hardness getting softer the further away from the edge. All the heat treating is done in the same place with the same amount of light and when it's a new product they are all hardness tested until I consistently get them right.
Screwdriver
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I assume you're not looking for ultimate hardness in these items which I also assume are all composite/laminated forge welds. That's very interesting info and I am guessing you're going for toughness in the blades rather than ultimate hardness for the keenest/sharpest result possible.
What level of hardness are you achieving with this process? At the tip compared to further away from the quench. Again my guess is this process almost mimics a case hardening of the hardenable insert piece so that the harness in the "join"tapers off to be almost as soft as the base metal.
I ask because I am tempted to try some forge welds, currently all my bladed items are homogenous hardening steels or mystery metal (springs, files, etc.)
<edit> It sounds like you are using residual heat to effectively anneal the items post edge quench. I have tried that technique myself out of laziness more that anything. My understanding is that if you're going to anneal a blade and draw back the temper, best to do it sooner rather than later. Would you know why that is exactly?
outofthefire
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They are all solid steel, the axes are drop forged rescue axes, the chisels are forged and ground (we also make tungsten tipped chisels) hammers are again just solid mostly all en 8 or 9. The hammers are made to BS 876 only the face is hardened it's all they need.I assume you're not looking for ultimate hardness in these items which I also assume are all composite/laminated forge welds. That's very interesting info and I am guessing you're going for toughness in the blades rather than ultimate hardness for the keenest/sharpest result possible.
What level of hardness are you achieving with this process? At the tip compared to further away from the quench. Again my guess is this process almost mimics a case hardening of the hardenable insert piece so that the harness in the "join"tapers off to be almost as soft as the base metal.
I ask because I am tempted to try some forge welds, currently all my bladed items are homogenous hardening steels or mystery metal (springs, files, etc.)
<edit> It sounds like you are using residual heat to effectively anneal the items post edge quench. I have tried that technique myself out of laziness more that anything. My understanding is that if you're going to anneal a blade and draw back the temper, best to do it sooner rather than later. Would you know why that is exactly?
Cheers. Ended up going blade type route. Too rich for my blood those. LolHand Forged Sickle - Etsy UK
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Screwdriver
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@outofthefire So "regular" edge quench, residual anneal?
