Author Topic: grinding  (Read 14725 times)

long carabine

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grinding
« on: August 16, 2008, 12:38:19 PM »
 I am not sure where to post this so I'll try here. Anyone make a knife from a file by grinding? Is it hard and a waste of time or is it sort of easy and a good way to spend a Sat. afternoon? Tim

northmn

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Re: grinding
« Reply #1 on: August 16, 2008, 02:47:51 PM »
Made a couple of knives by grinding.  Threw one file into a wood fire for a while to try to soften it a little.  Its a good way to spend more than one Sat afternoon.  One knife I made was a little patch knife and I made during breaks where I worked using very large heavy duty grinders.  It took a while.  The other was a plug bayonet I made to go with a musket I also made.  Threw that one into the fire.  It was still very hard to work with.  They stay sharp once you get them sharp, rust easily and are not even close to flexible.  Some files have more than 100 points of carbon.   To anneal one you have to let them cool in a medium like ashes for some time.  They did not anneal by heating red hot and then letting air cool.  It might wreck them as a file but they did not get soft by any means.

DP

Offline Dphariss

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Re: grinding
« Reply #2 on: August 16, 2008, 09:51:24 PM »
The best way is one of those wide flat belt sanders set horizontal with a coarse then finer belts gives very nice control. http://www.toolsnow.com/browse.cfm/4,146.html
Next would be a 2" high speed like we had at Shiloh. But this is a little expensive for most folks.
Very dead last would be a emery wheel grinder.
 And a bucket of water with any of the above.

I would forge, file and/or sand then polish.

Dan
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northmn

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Re: grinding
« Reply #3 on: August 16, 2008, 10:49:10 PM »
If you use a belt sander buy an extra sanding belt or two.

DP

Offline Rolf

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Re: grinding
« Reply #4 on: August 17, 2008, 09:17:58 AM »
Check if your file is carbon steel. If it is , go for it. But , a some cheap files are case harden mild steel and useless as knife blades.

Best regards

Rolfkt

Offline Ky-Flinter

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Re: grinding
« Reply #5 on: August 17, 2008, 05:53:57 PM »
Check if your file is carbon steel. If it is , go for it. But , a some cheap files are case harden mild steel and useless as knife blades.  Best regards,  Rolfkt

I've been considering the same type of project.....  How does one determine whether a file is carbon steel or mild?  BTW, I have heated the file cherry red and let it air cool, which I understand now, may not be enough.  Thanks,

-Ron
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Offline Rolf

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Re: grinding
« Reply #6 on: August 17, 2008, 07:43:43 PM »
You are soposed to be able to tell the difference between mild steel and carbon steel by looking at the sparks a grinder throws. They have a different color and shape. That said, I've never been able to relyably tell the difference that. Thats why I forge my knives from purchased steel stock and I store it labeled.
You could anneal a pice of the file and then try to harden it. If it stays soft, its mild steel.

Best regards

Rolfkt

northmn

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Re: grinding
« Reply #7 on: August 18, 2008, 02:46:25 AM »
Another way to tell is by brand.  Nicholson files are over 100 points carbon.  As stated if you heat it, and it gets soft its a cheap one.  As I understand it file knives were common.  I think maybe some of those big wheel foot grinders might make pretty short work of one as will a GOOD best sander. 

DP

J.D.

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Re: grinding
« Reply #8 on: August 18, 2008, 04:15:39 AM »
File  steel was a precious commodity on the fronter, so knives made from worn files were few and far between. IMHO, knives made from files were a rather late phenomenon.

That said, a file needs to fully annealed by evenly and slowly heating it to critical temp, to the point that a magnet will not stick. It then needs to be put in a bucket of lime or hardwood ashes that has been preheated by placing a red hot bar into the ashes. The file needs to be covered by about 6 inches of ash so's it cools slowly. The steel should still be slightly warm to the touch, the next morning.

At that point, the annealed file will be easy to grind or file. The knife blank will need to be re hardened in light oil and tempered  once the knife is profiled and the edge ground.

Offline Dphariss

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Re: grinding
« Reply #9 on: August 18, 2008, 04:58:25 AM »
File  steel was a precious commodity on the fronter, so knives made from worn files were few and far between. IMHO, knives made from files were a rather late phenomenon.

<snip>

This is something that is impossible to accurately comment on.
I suspect that files, used up or otherwise, were used where ever carbon steel was needed. Knifes may not have been a high priority item since knives were such a common trade item. But stating knifes made from files are only from a later date is simply not provable. If neatly done there would be know way to know if it started as a file or not.

Dan
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northmn

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Re: grinding
« Reply #10 on: August 19, 2008, 04:50:26 PM »
Steel was a very dear item in colonial days.  Much so that axes were made of wrought iron and steel shoed for an edge.  Hammers were often made the same way.  The biggest problem on commenting on what was or wasn't done is that there are so many ways of doing something.  Today we have the store bought mass produced mentality against a time when most things were hand made.  They made do with what they had and used what they had for the needs.  Not every used up file was made into a knife I am sure, but likely one was here and there.  Actually they do not make a top quality knife as they are too high in carbon and brittle.  They break too easily if used a a pry.  A good knife is made with a slightly flexible back and a harder edge.

DP

Offline Roger Fisher

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Re: grinding
« Reply #11 on: August 19, 2008, 06:18:12 PM »
Check if your file is carbon steel. If it is , go for it. But , a some cheap files are case harden mild steel and useless as knife blades.  Best regards,  Rolfkt

I've been considering the same type of project.....  How does one determine whether a file is carbon steel or mild?  BTW, I have heated the file cherry red and let it air cool, which I understand now, may not be enough.  Thanks,

-Ron
Use an old Nicholson!  You will spend a ton of time to get an edge although once sharp it's stay so although rusty also simply brittle and no good as a screw driver ::)
« Last Edit: August 19, 2008, 06:22:01 PM by Roger Fisher »

J.D.

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Re: grinding
« Reply #12 on: August 19, 2008, 07:25:33 PM »
File  steel was a precious commodity on the fronter, so knives made from worn files were few and far between. IMHO, knives made from files were a rather late phenomenon.

<snip>

This is something that is impossible to accurately comment on.
I suspect that files, used up or otherwise, were used where ever carbon steel was needed. Knifes may not have been a high priority item since knives were such a common trade item. But stating knifes made from files are only from a later date is simply not provable. If neatly done there would be know way to know if it started as a file or not.

Dan

Yes, it is nearly impossible to prove. I base my supposition, and that is all it really is, on the fact that trained blacksmiths were proficient in making their tools, including Files. IMHO, old worn files most likely would have been recycled into more valuable new files rather than recycled into relatively less valuable knives.

And the reason for attributing knives obviously made of files to a later date would be the more ready availability of relatively inexpensive, new  files, eliminating the need to "freshen" an old file due to the relative unavailability or relative expense of new tools.

Offline LRB

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Re: grinding
« Reply #13 on: August 19, 2008, 09:18:42 PM »
Steel was a very dear item in colonial days.  Much so that axes were made of wrought iron and steel shoed for an edge.  Hammers were often made the same way.  The biggest problem on commenting on what was or wasn't done is that there are so many ways of doing something.  Today we have the store bought mass produced mentality against a time when most things were hand made.  They made do with what they had and used what they had for the needs.  Not every used up file was made into a knife I am sure, but likely one was here and there.  Actually they do not make a top quality knife as they are too high in carbon and brittle.  They break too easily if used a a pry.  A good knife is made with a slightly flexible back and a harder edge.

DP
      Acually, a Nicholson file makes a very impressive knife. If properly heat treated, they are no more brittle than other knife steel, they will flex on an equal basis to any other, and hold a great edge. After the initial heat treat, they can be "soft backed" very easily, and be even more flexable. You can heat a Nicholson up to bright red, air cool, and drill with a cobalt bit, although a full anneal is better. A knife is NOT a pry bar, and should never be used as such, but if it were a do it, or die, the Nicholson blade will take tremendous side load pressure if soft backed. According to the Nicholson Company, their files are close to W1 in composition, and they advise heat treating as such. W1 is a fine knife steel.
    As far as historically correct, I agree with JD. There are apparent examples of file knives from the 18th c., but I would not believe them to be common. From what I have read, the English patented a file cutting machine, sometime in the late 1750's, if I remember correctly, but how many of those, and when, or if they got over here, I don't know. Many, or most American files were tediously hand cut, one line at a time, and then case hardened. A dull file was re-sharpened, not thrown away. Some were possibly made from blister steel. Mike Ameling would know more than I on this. But to sum it up, don't sell a file blade short. Properly HT'd, they make a great knife. Simmons files are also excellent. HT the same as a Nicholson.

J.D.

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Re: grinding
« Reply #14 on: August 21, 2008, 05:15:59 AM »
As an afterthought,  pretty good knives can made from wrought iron if properly forged and edge packed, so I wonder if there was an appreciable advantage to using a relatively expensive worn file to make a relatively inexpensive knife.

I dunno, just thinking...typing out loud, so to speak.

Offline rich pierce

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Re: grinding
« Reply #15 on: August 21, 2008, 11:02:50 PM »
Common butcher etc knives were very affordable during the flintlock and percussion periods.  If someone had a knife made by a smith duringn those periods then it may have cost more, not less, so perhaps it would have to be a special purpose knife.  Later on (Great Depression for example) people sometimes simply had no money and many knives were made in the 20th century from files.  Here is one I bought at a farm auction in the late 1960's.  It was called a "corn knife" by the auctioneer.  It's a real sticker with a hickory handle.  It is very hard and stout.  no way to tell how old it is, but I am leaning to 1870-1930.



It is easy to make a file-derived knife too brittle and too stiff. Better to have it more flexible and less brittle, so it won't snap when abused. They are easy to sharpen; harder to weld back together.
Andover, Vermont

Offline davec2

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Re: grinding
« Reply #16 on: August 25, 2008, 09:37:02 PM »
I have made a few knives from worn out files which I used to pick up at a local metal supply house.  They had a 55 gallon drum full, mostly very large, and they were 25 cents each.  I would just throw them in the fire place on a winter evening and fish them out of the ashes the next day.  This would always soften them enough to shape the blade easily by sawing, filing, and grinding.  The blade is then re-heat treated after is is completely shaped.  This is a boot knife I made about 30 years ago by this method.  Very good knife - holds an edge very well.



Some of the old files I bought were very thick and wide.  I forged those out to a rough shape first and, of course, if you heat and forge the blade, you can skip the annealing part of the process.  Don't know much about the old timers making knives out of files or horse shoes or fence wire, but it is fun to turn an old worn out file or power hack saw blade into something beautiful, new, and useful.
« Last Edit: January 05, 2020, 06:05:06 AM by davec2 »
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Offline Scott Bumpus

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Re: grinding
« Reply #17 on: August 25, 2008, 11:24:27 PM »
Nice knife dave!  The anount of talent represented on this board in so many different crafts is amazing. Maybe if I keep hangin around some of it will rub off on me.
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long carabine

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Re: grinding
« Reply #18 on: August 26, 2008, 01:27:20 PM »
 So i should heat before i grind, If i'm hearing this right. i remember making a knife from a old file in high school and we just put the file to the grinder then heated and dipped in water to cool. Tim

northmn

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Re: grinding
« Reply #19 on: August 27, 2008, 03:38:33 AM »
Probably regional, but the corn knife you show Rich is a far cry from the old Iowa corn knives I have seen.  They are about machete in size and have a flat point kind of like a cleaver.  They were used to whack corn ears in pieces.  I have one I inherited from my father.  When you talk about knife hardness I remember helping to butcher a pig and used my Gerber hunting knife.  Took about 30 minutes or better to get a sharp edge on it and about 5 for the sand in the hide to dull it.  A butcher knife set I inherited from my grandfather had blades of relatively soft steel but they would sharpen quick on a steel.  Real hard knives are not the panacea some think they are.

DP   

Dave Waters

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Re: grinding
« Reply #20 on: August 27, 2008, 02:30:23 PM »
Could some one tell me what IMHO means? I'm old and out of touch. ;D

Offline Ken G

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Re: grinding
« Reply #21 on: August 27, 2008, 02:46:34 PM »
Dave,
In My Humble Opinion - IMHO  We are are old and out of touch.  My kids keep me up to date on stuff.  Last night they were laughing at my wife for some of her Text message shortcuts.  I don't think we will every be hip again.   ::)
« Last Edit: August 27, 2008, 02:47:44 PM by Ken Guy »
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J.D.

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Re: grinding
« Reply #22 on: August 28, 2008, 06:11:39 PM »
So i should heat before i grind, If i'm hearing this right. i remember making a knife from a old file in high school and we just put the file to the grinder then heated and dipped in water to cool. Tim

Yes, heat the file to a bright orange red and cover with at least 6 inches of preheated hardwood ashes, anhydrous lime, or clean sand. I prefer lime or ashes.

Annealing makes the file much easier to grind. Re harden and temper after grinding.

A file that has not been tempered to relieve the brittleness of the file will chip in use, if not break when dropped or banged against something.

I don't remember the proper tempering temp for file steel. I'm thinking it is probably in the 500-550degree range, but don't take that to the bank.

If one does not want to go to all of the trouble of annealing, rehardening and tempering, the file can be tempered to probably 500-550 degrees and ground by holding the knife in your bare hands. Holding the knife in your bare hands will tell you when it is getting hot. Quench the file in cool water as you feel the heat begin to rise.

And Wick is right on about files making very good knives, if they are properly heat treated. Once the blade is tempered,  the back can be heated with a torch to a higher tempering temp to create a softer, springy back that will resist breakage.

The old way to get this selectively heat treated blade was to heat a thick iron bar in the forge and lay the back of the knife on the bar, watching the tempering colors as they run from the back to the point and edge.
« Last Edit: August 28, 2008, 06:23:18 PM by J.D. »

Dave Waters

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Re: grinding
« Reply #23 on: August 29, 2008, 10:55:39 PM »
Thanks Ken
« Last Edit: August 29, 2008, 10:56:14 PM by Dave Waters »

ottawa

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Re: grinding
« Reply #24 on: September 07, 2008, 01:40:12 AM »
a good book for the beginner wanting or thinking about knife making is the 50$ knife shop by Wayne Goddard's hase some good ideas for a shop and a short run down on making small forges fro knife making .everything from heating like was mentioned til a magnit wont stick and soforth
 I've been making knives for a few years now mostly self taught and what i could pick up hear and there this book is very helpfull
Ben