Reprofile a tool or knife of hardened Steel, fast, and without machines?

HeavyHanded said:
I guess I'll be one of the few advocating the use of files for this job, and for most jobs on low RC steel tools intended for hard use. I use files for setting bevels on my machetes, lawnmower blades, hatchets and axes, digging tools. I'd recommend cleaning any dirt off the tool first, and then firmly clamping the tool to a solid surface. Once the file begins to catch, it removes steel very quickly and cleanly and with a lot of control. Even with a coarse belt grinder, I'm not sure I'd want to put the wear and tear on it for a job like the one described when it can be easily done with a file.

The combination stones will be slow going by comparison. I wouldn't even use my 80 grit boat stone for a job like this, a 12" mill bastard will make short work of it.
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+1
A file is the best tool for putting an edge on digging implements like a shovel or mattock. A "canoe" or "puck" style stone can be used to refine the edge or for everyday touch ups but it's a waste of time to use them for the initial reprofiling.
 
Files are made for sharpening tools like this. A $10 file will last a very long time sharpening garden tools. Files are very efficient at removing metal.
I use them all day long in my shop. I have dozens of files. They are tools to remove metal-it doesn't matter where the metal is. When they wear out, you buy a new one.
 
A file will do fine for working on a mattock. F. Dick makes nice files, so the one you have should work well. Just always remember that the file must be harder than the material it is filing. Knives are often hard enough for files to have little effect, but high-impact tools like mattocks, machetes, hoes, many (not all) axes, etc. are able to be worked easily with a good quality file.
 
Well, I have sent the Dick back.
I had not even tried it on the Mattock after seeing how ineffective was it on 58HRC 8cr14mov Sanrenmu.
But, as I had not fixed the knife but just hold it with my hand, and used the file one handed, that my be one reason why I failed instead of filed.
And, no, I did not yet try the Lansky 120 Diamond, because I thought it was not able to take away so much material. You must consider, reprofiling a mattock is not like reprofiling a knife. The material to remove is a LOT more.
Now, you may still be right, maybe the stones or the 120 Diamond would be faster than a File even on soft steel, i did not try, so I cannot say yes or not.
But, that's what I have thought in that moment.

So, I understand that a File, even a 72HRC Titan one, is not ok for hardened metal.
I see that some of you like files for soft metal, so, I suppose I will go for a file and I will see how it compares with my Lansky The Puck.
I may still buy a coarse stone if not expensive (first time I am in negative before the half of the month).

About files, and using them for tools: would a Titan File be a good thing?
It is very hard, 72hrc. But it is only coated. Now, I do not think it may get damaged. It is a GOOD File, Vallorbe. Same quality as Dick. And it is sold as "good for hardened steel", so it should not get damaged with softer steel. And by being harder than normal Files, it should give me more tolerance in case some tool (spades) are a bit harder, or things like that. Right?
Besides I have read that the Valtitan have negative geometry r something like that. This is supposed to make it easier for them to file hard material. While supposedly the positive geometry of the normal files is better for soft material. Anythoughts about this?
Also, which "grit" do you suggest?
I had a hard time understanding (and finally did not understand) something I have read about the fact that the harder the materialto file, the finer the file must be.
For stones and diamant is not so.
I was sure I had to take a very very coarse file to be faster.
You with experience, which "grit" would be better for filing tools?
 
The harder the steel, the more likely it will be to chip and also to damage an overly aggressive file.

Most files are ranked in terms of grit by overall size, the larger the file the more aggressive it will be. Also differences between single and double cut. I would not consider using a double cut on even mildly hardened steel - a single cut mill file works great.

Personally I view the more expensive files as being for specific tools. If I were doing a lot of work with a machete or saw blade of known RC and steel type and wanted to maintain with one tool, I'd select a good quality file. For general work where I might wind up using it on something too hard for it etc, I prefer less expensive files - not the bottom of the barrel, but mid range.
 
HeavyHanded said:
I guess I'll be one of the few advocating the use of files for this job, and for most jobs on low RC steel tools intended for hard use. I use files for setting bevels on my machetes, lawnmower blades, hatchets and axes, digging tools. I'd recommend cleaning any dirt off the tool first, and then firmly clamping the tool to a solid surface. Once the file begins to catch, it removes steel very quickly and cleanly and with a lot of control. Even with a coarse belt grinder, I'm not sure I'd want to put the wear and tear on it for a job like the one described when it can be easily done with a file.

The combination stones will be slow going by comparison. I wouldn't even use my 80 grit boat stone for a job like this, a 12" mill bastard will make short work of it.
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I agree, I break out a pferd for stuff like this quite often.
Russ
 
Sir Joe said:
Well, I have sent the Dick back.
I had not even tried it on the Mattock after seeing how ineffective was it on 58HRC 8cr14mov Sanrenmu
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Theres a huge difference between an 8cr14 @58rc knife blade and a mattock blade which is usually something like 1045 @40rc! Try the file I think you will be pleasantly surprised.
 
Good, I will go for the file and for a very coarse stone.
The Puck by Lansky and even the Lansky Diamond 120 are immensely slooooooooooooooooow. No f...ing way they can be used to reprofile a Mattock, no matter how soft the steel is.
Just too much steel to take away.
For istance I will at first experiment with the files we have here at Work, old ones, supposedly good. If they work even a bit, I may be tempted to buy a Valtitan. Which I want to try on hardened steel just even to see it is true what Vallorbe says.
I will buy a medium grit in that case, as I understood that too coarse is not good on hard things.

In these days I have started practising with the SharpMaker on knives and Shears. I am very pleased with it. Although the rods move quite a lot.
The Lansky Diamond 120 was good to quickly remove a bevel and also to make an edge on the other side of a "one sided" knife (I hate knives with edge on one side only).
I have to practise more and more, but, I was able to bring the knife to cutting paper level.
Considering I am a total beginner, I am ok with the results.
 
You don't need any special/expensive files to cut the soft steel mattocks are made of, a simple $10 Nicholson 06706 will do the job just fine.
 
I haven't tried the Pherd files as yet but intend to. I can say that the Bacho files are very good. The double cut second cut file would do well for the OP's purpose. Smooth and precise.
 
If you want to re-profile a knife by hand, I would use a Norton Crystolon coarse stone with lots of mineral oil. It is quite a bit faster than a 250 grit waterstone, a coarse India stone, an Atoma 140 plate, or a DMT XXC plate. When I am near zeroing the FFG grinds on production folders, this is the stone I turn to.
 
Steel_Drake said:
If you want to re-profile a knife by hand, I would use a Norton Crystolon coarse stone with lots of mineral oil. It is quite a bit faster than a 250 grit waterstone, a coarse India stone, an Atoma 140 plate, or a DMT XXC plate.
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Are you saying "quite a bit faster" than everything you listed? Significantly faster than a DMT XXC plate? That's pretty hard to believe. The particle size should be similar from Coarse Crystolon to DMT XXC. But the XXC should dig deeper due to particle shape.

I have a Medium Crystolon and it cuts pretty fast. I would expect the coarse to cut faster for sure. But faster than an XXC? I'd be surprised if it was even *as* fast.

Please note, I'm just kind of saying what is occurring to me. I haven't tried a Coarse Crystolon and I'm not saying you're wrong. I'm asking for more details and clarification, albeit with some skepticism. :)

Brian.
 
As far as I am led to believe, a coarse Crystolon is around 90-grit, but the largest advantage in extended use is the stone is very friable and thus constantly exposes fresh grit in use. Diamond plate abrasives tend to wear down over time and lose some of their initial cutting speed. That plus the grit difference seems to account for the speed difference.

One thing to note is that it is imperative that you use mineral oil liberally with the stone to prevent loading.
 
bgentry said:
Are you saying "quite a bit faster" than everything you listed? Significantly faster than a DMT XXC plate? That's pretty hard to believe. The particle size should be similar from Coarse Crystolon to DMT XXC. But the XXC should dig deeper due to particle shape.

I have a Medium Crystolon and it cuts pretty fast. I would expect the coarse to cut faster for sure. But faster than an XXC? I'd be surprised if it was even *as* fast.

Please note, I'm just kind of saying what is occurring to me. I haven't tried a Coarse Crystolon and I'm not saying you're wrong. I'm asking for more details and clarification, albeit with some skepticism. :)

Brian.
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Brian, something I've been aware of for a few but have only recently begun to make use of - diamond hones, especially the coarser ones will glaze somewhat with steel. A lot of folks recommend Barkeeper's Friend, Scotchies etc to clean them. I've taken to cleaning them with a few light circular passes with a fine SiC stone and water. More recently I've taken to leaving the left over SiC dust on the diamond plate. I do not believe the SIC contributes much to grinding as the plate still feels extremely coarse and grinds aggressively (XXC DMT), and the fine SiC is smaller to begin with and what's on the plate is fragments of the original grit. What I have noticed is that on extended grinding it keeps the plate cutting clean and uniform compared to using with just water.

The center part of the plate had become somewhat tame, but after being hit with the sic stone and the mud left to roll around on the surface it was super aggressive - almost "like new". I've been doing a bunch of plane irons and chiseles and had to true them up on a grinder to start. After being ground back down on a coarse belt to a new bevel, they needed to be flattened to zero and the XXC DMT is perfect for this - I can go right from that to my 240 King and on to my finer JWS from there.


The coarse Crystalon works great and I have used it on some tough regrinds (with mineral oil of course). For me the XXC DMT is the best in my tool box for this sort of thing - to the point where I won't use it for lapping my waterstones - is a dedicated rough grind flattener for tougher/harder steels.
 
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