# Making Knives From Files



## cotedupy (Apr 5, 2021)

So I think I've seen this done before. Anybody tried it and have any tips? In particular: 

Is it a stupid idea just trying to do this amount of stock removal if I only have a belt sander? Will it make me want to kill myself? / Spend a silly amount of money on belts?

If I took an angle grinder to them, to make the shape, am I going to f-up any ht they have?

In the unlikely event I didn't balls it up, would they still be c**p anyway...?


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## gregfisk (Apr 5, 2021)

I made a knife from a file as a kid many many years ago. My Grandpa used to make fishing knives with them. I think it’s a fun project if you want to try something new. My guess is the end blade probably won’t hold an edge all that well but I’m not sure. With a belt grinder you shouldn’t have any problem grinding them down. Just don’t let them get too hot so the steel doesn’t soften up.


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## Knivperson (Apr 5, 2021)

Chealsea Miller does it, right?


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## KingShapton (Apr 5, 2021)

You will have to redo the wb of a file anyway. Files are so hardened, highly hardened, that they are too brittle as knives. But they are good as a starting material.


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## KingShapton (Apr 5, 2021)

But I'm not an expert on that, I just repeat things that I've read from others.

Maybe it's worth a try too, what have you got to lose?


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## Bensbites (Apr 5, 2021)

In my opinion I would rather buy known steel of the proper thickness. You then don’t need to anneal and can use a known Ht protocol. 
This can be done, I have trouble thinking it’s worth the effort.


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## inferno (Apr 5, 2021)

maybe grind a small part first to see if its doable with what you have. 
if anyone knows what alloy it is you can always temper to lower hardness in your oven. if these are too hard/brittle now i mean


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## Corradobrit1 (Apr 5, 2021)

Knivperson said:


> Chealsea Miller does it, right?


She uses rasps. Totally different


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## RDalman (Apr 5, 2021)

Yes you dont want to do that amount of stock removal on a hardened file, they're probably near 65 hrc. You can anneal them though if you have some place you can make a decent sized fire. Put them in the center and build a pretty big fire on top. Leave them with the ashes to the next day and you should have them soft and easy to grind. After rough grinding you can heat treat them in the grill with charcoal given some extra airflow (think hairdryer/heatgun/shopvac on blow) cherry red (magnet or if dark out you can watch decalescence also, that's about 760 shoot for a little north of 800)and quench in warm (~70c) canola. Or slightly below 800 and lukewarm brine if you're feeling frisky. Feel them with a file that you got them harder than that. Temper in convection oven at 160-240c depending on desired hardness. 1x2 or 1x3h.


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## Slim278 (Apr 5, 2021)

I think an old leaf spring would make good knives. From what I understand pre 1960 are most almost always 5160.


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## cotedupy (Apr 6, 2021)

Thanks all for these insights!

It sounds like a little project for when I have less work on. I should be able to anneal them and then do some kind of vague HT, as per @RDalman 's advice I think. So might be fun to see if it works out in any way at all.

Anybody tried HT in a ceramic egg Kamado BBQ? I reckon I could get mine up to 750/800 degs (I've had at 650 just with both vents open), plus it has a temp gauge on it...


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## aboynamedsuita (Apr 6, 2021)

There’s a knife maker in my part of Canada who does knives of files and sawblades, pretty popular at the local tradeshows and has a presence elsewhere too. I’ve had one but sold it to a buyer in Oz, they’re actually usable as kitchen knives (and prices are much more realistic than CM lol)

EDIT I believe he does some forging though


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## nwshull (Apr 6, 2021)

Corradobrit1 said:


> She uses rasps. Totally different


For chef knives sure... but some also like a petty.


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## RDalman (Apr 6, 2021)

cotedupy said:


> Thanks all for these insights!
> 
> It sounds like a little project for when I have less work on. I should be able to anneal them and then do some kind of vague HT, as per @RDalman 's advice I think. So might be fun to see if it works out in any way at all.
> 
> Anybody tried HT in a ceramic egg Kamado BBQ? I reckon I could get mine up to 750/800 degs (I've had at 650 just with both vents open), plus it has a temp gauge on it...


Ceramic egg should be perfect for anneal also! You want to reach a little north of 700, and get a as slow cooldown as possible, should work to close it up and let the blade be on the coals. 
Just be wary of potential damage to coal container and such if you put extra air to it. Too much airflow and you easily melt steel.


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## VICTOR J CREAZZI (Apr 6, 2021)

I'm guessing that cotedupy is talking F. and Robin is most definitely talking C. 

Just sayin'.


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## inferno (Apr 6, 2021)

kelvin guys. kelvin.


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## VICTOR J CREAZZI (Apr 6, 2021)

inferno said:


> kelvin guys. kelvin.


?????


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## big_adventure (Apr 6, 2021)

VICTOR J CREAZZI said:


> ?????



When you are talking temperature, it's "always" best to use Kelvin as the unit. It's the same unit base as C but instead of being based on the freeze point of water, it's based on absolute 0, which is -273C. So 273K = 0C. 373K = 100C. Negative numbers are impossible, because absolute zero is "atomic motion stops" so you can't go below that.


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## inferno (Apr 6, 2021)

VICTOR J CREAZZI said:


> ?????


The *kelvin* is the base unit of temperature in the International System of Units (SI), having the unit symbol K. It is named after the Belfast-born Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907).

The kelvin is now defined by fixing the numerical value of the Boltzmann constant k to 1.380 649×10−23 J⋅K−1. Hence, one kelvin is equal to a change in the thermodynamic temperature T that results in a change of thermal energy kT by 1.380 649×10−23 J.[1]

The *Kelvin scale* fulfills Thomson's requirements as an absolute thermodynamic temperature scale. It uses absolute zero as its null point (i.e. low entropy). The relation between kelvin and celsius scales is _T_K = _t_°C + 273.15. On the Kelvin scale, pure water freezes at 273.15 K, and it boils at 373.15 K.

Unlike the degree Fahrenheit and degree Celsius, the kelvin is not referred to or written as a degree. The kelvin is the primary unit of temperature measurement in the physical sciences, but is often used in conjunction with the degree Celsius, which has the same magnitude.


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## big_adventure (Apr 6, 2021)

inferno said:


> The *kelvin* is the base unit of temperature in the International System of Units (SI), having the unit symbol K. It is named after the Belfast-born Glasgow University engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907).
> 
> The kelvin is now defined by fixing the numerical value of the Boltzmann constant k to 1.380 649×10−23 J⋅K−1. Hence, one kelvin is equal to a change in the thermodynamic temperature T that results in a change of thermal energy kT by 1.380 649×10−23 J.[1]
> 
> ...



There you go, making my reply look all pedestrian and ****. Thanks. Thanks a lot.


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## inferno (Apr 6, 2021)

i just copied it from wikipedia.


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## big_adventure (Apr 6, 2021)

inferno said:


> i just copied it from wikipedia.



Given the embedded colorful links, I assumed it was copied from somewhere. If not, that was a crapton of unnecessary work.


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## VICTOR J CREAZZI (Apr 6, 2021)

I don't think it will catch on. It would be like trying to get people to stop calling pattern welded steel 'Damascus'.


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## cotedupy (Apr 6, 2021)

VICTOR J CREAZZI said:


> I'm guessing that cotedupy is talking F. and Robin is most definitely talking C.
> 
> Just sayin'.



Ah we don't have Farenheit where I'm from... I was talking celsius too, those things get hot! To clean after use I open all the vents to burn it all out and it gets to about 650, and that's after 8 hours cooking so there's not much charcoal left. I reckon with a full tank it'd go a fair bit higher.

I'll take RD's advice and have a little read on what they can go up to. Though there's very little metal there - without the grill then the whole of the inside is ceramic.


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## big_adventure (Apr 7, 2021)

VICTOR J CREAZZI said:


> I don't think it will catch on. It would be like trying to get people to stop calling pattern welded steel 'Damascus'.



That's not remotely the same thing. Communication is a protocol where we agree upon certain rules, and, in our tiny world, one of those rules is the shorthand that "damascus" steel means pattern-welded steel. It's completely established now, and we're not going back - "damascus" now means that, in accepted communications.

When it comes to measuring temperature, all three scales are absolutely valid. 0K = -273.15C = -459.6F. One degree C _or_ K is the temperature change you get when applying one calorie to one gram of pure water. Using any of them is "OK" - it's just easier to use K when you are doing anything complicated to avoid using negative numbers.


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## Dhoff (Apr 7, 2021)

big_adventure said:


> When you are talking temperature, it's "always" best to use Kelvin as the unit. It's the same unit base as C but instead of being based on the freeze point of water, it's based on absolute 0, which is -273C. So 273K = 0C. 373K = 100C. Negative numbers are impossible, because absolute zero is "atomic motion stops" so you can't go below that.



I cannot help myself, apologies:









Quantum gas goes below absolute zero - Nature


Ultracold atoms pave way for negative-Kelvin materials.




www.nature.com





And the original article it discusses:






Science | AAAS







science.sciencemag.org


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## big_adventure (Apr 7, 2021)

Nah, don't worry about it. Quantum physics has explicitly different rules than "normal" newtonian "macro" physics.


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## Bolek (Apr 7, 2021)

big_adventure said:


> That's not remotely the same thing. Communication is a protocol where we agree upon certain rules, and, in our tiny world, one of those rules is the shorthand that "damascus" steel means pattern-welded steel. It's completely established now, and we're not going back - "damascus" now means that, in accepted communications.
> 
> When it comes to measuring temperature, all three scales are absolutely valid. 0K = -273.15C = -459.6F. One *degree* C _or_ *K* is the temperature change you get when applying one calorie to one gram of pure water. Using any of them is "OK" - it's just easier to use K when you are doing anything complicated to avoid using negative numbers.


There is no such a think as a degree K (only a K).


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## cotedupy (Apr 7, 2021)

big_adventure said:


> That's not remotely the same thing. Communication is a protocol where we agree upon certain rules, and, in our tiny world, one of those rules is the shorthand that "damascus" steel means pattern-welded steel. It's completely established now, and we're not going back - "damascus" now means that, in accepted communications.
> 
> When it comes to measuring temperature, all three scales are absolutely valid. 0K = -273.15C = -459.6F. One degree C _or_ K is the temperature change you get when applying one calorie to one gram of pure water. Using any of them is "OK" - it's just easier to use K when you are doing anything complicated to avoid using negative numbers.



I think Victor might have been being a little flip there!


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## big_adventure (Apr 7, 2021)

Bolek said:


> There is no such a think as a degree K (only a K).



So, what you are saying is...

...literally exactly what I wrote.


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## VICTOR J CREAZZI (Apr 7, 2021)

big_adventure said:


> That's not remotely the same thing. Communication is a protocol where we agree upon certain rules, and, in our tiny world, one of those rules is the shorthand that "damascus" steel means pattern-welded steel. It's completely established now, and we're not going back - "damascus" now means that, in accepted communications.
> 
> When it comes to measuring temperature, all three scales are absolutely valid. 0K = -273.15C = -459.6F. One degree C _or_ K is the temperature change you get when applying one calorie to one gram of pure water. Using any of them is "OK" - it's just easier to use K when you are doing anything complicated to avoid using negative numbers.





cotedupy said:


> I think Victor might have been being a little flip there!


I'm just saying that convention has weight. If the majority of metallurgy literature is in Celsius, or Fahrenheit, the majority of the people using the materials are going to keep using those systems. Maybe I'm reading the wrong material, but I'm pretty sure that I've never seen Kelvin used in the metallurgy books that I read.

I suppose that with cryo becoming more common there is some sense to using it, but there is a strong momentum to convention. For a time I always referred to 'pattern welded steel' as such or PWS, but then realized that I was spending way too much time explaining why I was calling damascus PWS. If you're the only guy in the group who always talks in Kelvin, you're going to be 'that guy'.

You have given me reason to commit -273.15 to memory though, in case I run in to 'that guy'.


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## cotedupy (Apr 7, 2021)

Well I for one am amused by how this thread has become a heated (ho ho) discussion regarding the relative merits and demerits of units of temperature .


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## big_adventure (Apr 7, 2021)

VICTOR J CREAZZI said:


> I'm just saying that convention has weight. If the majority of metallurgy literature is in Celsius, or Fahrenheit, the majority of the people using the materials are going to keep using those systems. Maybe I'm reading the wrong material, but I'm pretty sure that I've never seen Kelvin used in the metallurgy books that I read.
> 
> I suppose that with cryo becoming more common there is some sense to using it, but there is a strong momentum to convention. For a time I always referred to 'pattern welded steel' as such or PWS, but then realized that I was spending way too much time explaining why I was calling damascus PWS. If you're the only guy in the group who always talks in Kelvin, you're going to be 'that guy'.
> 
> You have given me reason to commit -273.15 to memory though, in case I run in to 'that guy'.



Hahaha

No worries at all. If you are to the point of discussing specific temperatures for specific chemical operations, you should probably be aware of K anyway - even if you don't use it in normal discussions. You almost certainly learned K when you were in high school physics or chemistry or both, and likely just forgot about it, as it's not used day to day. 

I never use K when I talk to regular human beings (or pets, or walls, or my knives...).

That all has nothing to do with my point though: using K or C or F doesn't matter as long as both sides understand which scale they are on. You can do every single kind of operation using any of them. If one is going to care significantly about physics or chemistry, one should at least know and understand K, but it's not really required. All three systems measure temperature, and 2 of the 3 are the same exact system except they start at a different "0." The "Damascus isn't really damascus" argument just doesn't work like that. Modern language inside the hobby/industry (that protocol of communication I referenced above) accepts that "damascus" steel is "pattern-welded steel" and, moreover, more people will use the term damascus than PWS. Thus, if you want to communicate to most audiences, you should use the term "damascus" as "PWS" won't actually work - that, or you will spend a ton of time explaining what you are talking about for literally no added benefit.


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## inferno (Apr 7, 2021)

ok guys i'll see your "damascus" and raise you a rankine!  the bestest ever temp scale.






Rankine scale - Wikipedia







en.wikipedia.org


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## ian (Apr 7, 2021)

cotedupy said:


> I reckon I could get mine up to 750/800 degs (I've had at 650 just with both vents open), plus it has a temp gauge on it...



Wow, seriously? My green egg has gotten up to 900F=480C, but I don't think I've ever gotten it as hot as 650. What's your secret? You get better airflow on yours?

----

Also, I measure temperature using the units G = F + C^2 - 32, where F=Fahrenheit, C=Celsius and G stands for Gerbil. Water freezes at 0 Gerbils and boils at 10180 Gerbils. Comfortable room temp is 436 Gerbils.

(This conversation is ridiculous! Also, feel free to freeze 0 gerbils but never boil 10180 gerbils.)


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## BillHanna (Apr 7, 2021)

inferno said:


> ok guys i'll see your "damascus" and raise you a rankine!  the bestest ever temp scale.
> 
> 
> 
> ...


FAH REN HEIT. FAH REN HEIT. *FAH REN HEIT!  *


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## swarfrat (Apr 8, 2021)

big_adventure said:


> ....When it comes to measuring temperature, all three scales are absolutely valid. 0K = -273.15C = -459.6F. One degree C _or_ K is the temperature change you get when applying one calorie to one gram of pure water. Using any of them is "OK" - it's just easier to use K when you are doing anything complicated to avoid using negative numbers.


That's it, from now on I'm reporting all temperatures in degrees _Rankine_.


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## cotedupy (Apr 8, 2021)

Entries are now closed for KKF Post of the Year 2021. I assume admin have already started engraving your name on the trophy Ian.




ian said:


> Also, I measure temperature using the units G = F + C^2 - 32, where F=Fahrenheit, C=Celsius and G stands for Gerbil. Water freezes at 0 Gerbils and boils at 10180 Gerbils. Comfortable room temp is 436 Gerbils.
> 
> (This conversation is ridiculous! Also, feel free to freeze 0 gerbils but never boil 10180 gerbils.)



p.s. Yeah mine easily goes to 650 with not much charcoal when I'm cleaning. And I've cooked pizzas on it at 500 (not recommended - I learnt later that the humble pizza stone is meant to be used at around 300. As evidenced by the loud crack when ours broke when cooking the final one. Good pizza though, and takes about a minute to cook).

Umm, no particular secret no. Mine's a Kamado Joe, and I think they're modelled fairly closely on BGEs, so I shouldn't have thought the airflow is any better.


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## Luftmensch (Apr 9, 2021)

For what it is worth...

... I attempt to use "pattern welded steel" instead of "damascus" wherever I can.

Me? I cook in Fahrenheit, measure daytime temperatures in Celsius, do chemistry in Kelvin, set my thermostat to Réaumur and have arguments in Rankine. Have to keep life simple... you know??


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## Dhoff (Apr 9, 2021)

Lets derail it further by mentioning the totally absurd system of measuring in feet, inches, hands etc.

My kids feet are way smaller than mine! We constantly argue whether I'm 100 feet tall or just 6 feet.


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## Luftmensch (Apr 9, 2021)

Dhoff said:


> My kids feet are way smaller than mine! We constantly argue whether I'm 100 feet tall or just 6 feet.



Surely it is the King's feet??!!


Steering the thread back on track 

I definitely wouldnt do stock removal on the hardened file. You'll likely ruin the heat treat by working too hard and you'll curse a lot from how stubborn the material is. If you are annealing the file, @Bensbites advice of using a known steel makes even more sense! You may as well just buy annealed stock and skip a step!

Of course there is nothing wrong with being a have-a-go hero. I would just do what you could to maximise the odds of getting a usable blade out the other end!


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## Dhoff (Apr 9, 2021)

Luftmensch said:


> Surely it is the King's feet??!!
> 
> 
> Steering the thread back on track
> ...



We do not have a King in Denmark only a Queen 

OT: Maybe you are lucky enough to have a company making blanks like jaredtoddknives. Do not know if he ships internationally


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## RDalman (Apr 9, 2021)

There's the possibility of joy of repurposing also.


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## cotedupy (Apr 9, 2021)

Luftmensch said:


> Surely it is the King's feet??!!
> 
> 
> Steering the thread back on track
> ...



Ah yes indeed... I have done one from proper steel, but as @RDalman said - it's about the fun of recreating something anew!

I rather enjoyed this (which didn't involve annealing or ht): Sheep Shear Debas (?) So thought maybe I'd have a try at something a bit more challenging


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## inferno (Apr 9, 2021)

i agree with others that its probably more practical to simply buy steel and make the knife from that.
its also more practical so simply buy knives instead of making them yourself.

but its more fun to make something from something else! i have lots of bearing races and other scrap steel that i have "test hardened" to see if its usable. and this summer i will make something out of this material.

you could just heat the files it until it turns soft enough to work, then when almost done grinding, HT it. check the grain. if its good then you're done! if its not you need to do more operations. and then its too late to abandon the project since you invested so much time already so now you have to make it work


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## Luftmensch (Apr 10, 2021)

Dhoff said:


> We do not have a King in Denmark only a Queen



Neither do the rest of us in the Commonwealth! (Perhaps somewhat more so after yesterday). Fun fact (I am sure you know), your Princess is Australian!




Dhoff said:


> OT: Maybe you are lucky enough to have a company making blanks like jaredtoddknives. Do not know if he ships internationally



Not to the same configurability but there are some stores that sell knife project blanks.




cotedupy said:


> I rather enjoyed this (which didn't involve annealing or ht): Sheep Shear Debas (?) So thought maybe I'd have a try at something a bit more challenging



Cool project. Very 'strayan'!!!

Repurposing is a lot of fun. @RDalman gave you some pretty good notes on annealing and heat-treat.

Going back to your earlier questions



cotedupy said:


> Is it a stupid idea just trying to do this amount of stock removal if I only have a belt sander? Will it make me want to kill myself? / Spend a silly amount of money on belts?



If you anneal the steel you wont need too many belts. Get a couple of good quality (Norton blaze, Klingspor) low grit (40-60) belts and hog away. If it is the same belt sander as your Deba project, you can get decent belts in that size. Although the belt sander is underpowered, you can work within its limitations and eventually get the job done (I essentially have the same model as you).



cotedupy said:


> If I took an angle grinder to them, to make the shape, am I going to f-up any ht they have?



Probably... It depends what you put on the end of them. The composite discs (vitrified bonds?) can locally raise the temperature of the steel very quickly. They put a heck of a lot of energy into a small surface area when cutting. If you don't have speed control, they naturally have high RPMs. You can approximate the cutting temperature by the colour of the oxides left on the steel. It is easy to create localised blue oxide - aka 300C. When you are grinding using the face of the disk, it is easier to control heat. Same with flap disks. They are more like a belt sander - the heat is distributed over a larger area and takes longer to build up.

... but again. None of this matters if you are using annealed steel!!


Seeing as you are limited by the shape of the files (unless you forge them thinner and taller - next level stuff for a beginner!!), I would make a Suji from the big file and a petty from the small file. Your grind and cuts wont need to be too complex

Looking forward to your efforts


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## RDalman (Apr 10, 2021)

Here's one of my grandfathers files


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## Luftmensch (Apr 10, 2021)

RDalman said:


> Here's one of my grandfathers files



What a gorgeous way to preserve a family tool that would have otherwise probably rusted! I love the hamon. Is the sori real or forged into the spine??

@cotedupy... the bar has been set


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## RDalman (Apr 10, 2021)

Luftmensch said:


> What a gorgeous way to preserve a family tool that would have otherwise probably rusted! I love the hamon. Is the sori real or forged into the spine??
> 
> @cotedupy... the bar has been set


No I forged it curved backwards intentionally.


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## VICTOR J CREAZZI (Apr 10, 2021)

I'd say " Anneal the old file as good as you can in the barby (anything that you do will be better than file hard). Grind away with what ever tools you have or can get together and you'll see what works
 
(there are several knife makers who do quite well with 4" angle grinders, I think they have a guild or something)

Meanwhile start asking around about blacksmithing groups in your area and you'll likely meet someone to HT for you or let you use their stuff to do it yourself.


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## cotedupy (Apr 10, 2021)

Luftmensch said:


> What a gorgeous way to preserve a family tool that would have otherwise probably rusted! I love the hamon. Is the sori real or forged into the spine??
> 
> @cotedupy... the bar has been set



Ha! Yes... it does look like I've rather committed myself now doesn't it!

And actually @VICTOR J CREAZZI makes a good point... I do know knifemaker not far from here (seriously nice guy), who does proper pro ht, and has said that I'm welcome to come use any of his kit whenever I fancy. I should really take him up on that eh!


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## cotedupy (May 2, 2021)

ian said:


> Wow, seriously? My green egg has gotten up to 900F=480C, but I don't think I've ever gotten it as hot as 650. What's your secret? You get better airflow on yours?
> 
> ----
> 
> ...



We've been without our Kamado all year, as we moved house and it took a while getting round to picking it up from the in-laws' place. When I looked at the temp dial the other day I was actually misremembering - when I burn it out at the end of a cook, it goes to about 650 f, not c. 

I did cook pizzas at 500 c, but that's about as high as the dial goes by the look of it. So maybe suitable to soften steel, but not to do HT.

(Just to reassure you that I don't have some special secret / crazy-ass bbq )


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