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File with teeth ground off from estate sale

2279 Views 14 Replies 8 Participants Last post by  Gofor
I have a file with teeth ground off from an estate sale. It is with some basic woodworking tools. I assumed it was used as a scraper. I ran across it today and tried it. It does not scrape. Any one have any ideas of what else it may have been used for?
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Difficult to say with out seeing it, could it have been used as an improvised turning tool for a lathe. I have seen these used as a lathe tool when their useful life as a file has expired. the only problem is, with them being tempered for their intended use, they are brittle and snap quite easily.

Just a thought.

How are you keeping anyway, you still on the free lunch trail?

Cheers mate

What shape and size file? Is it rough ground, or polished? Are the corners squared, or flat?

I used a broken triangular file to make a tirangular burnisher for scrapers (don't really like it). I think I will round off at least one corner and try it again.

I have a hunting knife my uncle made from a flat file.

Files are made from some very tough stock that can be ground down quite a ways before it gets too soft to hold an edge. Maybe somebody had plans on making some sort of cutting tool with it. It is too brittle to be used for prying or twisting.
This is an interest subject Bob. I remember reading somewhere that you can make a lot of edge tools from files, but before grinding them and bending them they should softened up.

The article I read said that to do this softening you can put the file in your kitchen oven at X degrees for X hour(s). I can't remember how hot the oven needs to be or the timing. A search on the net might turn up something.

After grinding, bending etc. the file needs to be heated up with a torch until it's straw/brown color and then doused in water or oil to re-harden it.

I'm going to have a look now to see if I can find anything about the process.

Well I did find one article about making a knife from a file. The file had to be softened first by heating it to a yellow/orange color first in a campl fire, then removed from the fire and left to cool slowly (called annealing). The next step was to grind and sand it to the knife shape and then it was again put into the fire to re-harden it until reaches a light orange color, then thrust into a bucket of motor oil and stirred around for awhile before leaving it to fully cool in the oil leaning it against the inside of the can. The last step was tempering which was again heating to a wheat color with a propane torch.

The info is similar but doesn't entirely match up very well with the article I mentioned above. It would be interesting find out which method is best or if they both work well. I still have the article somewhere. Probably in one of my old turning books. Meanwhile here is the link to the knife making article.

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Sorry Bob, I got off track and didn't answer your question The old file could have been used to burnish a lathe scraper tool or to burnish the edges of a cabinet scraper. Burnishing is turning a straight edge into a very small and sharp almost microscopic hook. This allows your lathe scraper to put a beautiful smooth finish on the inside of a bowl for example.
I'd bet on the burnisher as well. The steel in a file is normally over 65rc hardness. Carbide, by comparison, is usually over 73rc. Good HSS (high speed steel) used in chisels, drill bits, and plane irons typically might be hardened to about 59 to 62rc. Plain old high carbon tool steel might be around 45 to 47rc. The point of all this is to say that, to be a burnisher, the file metal would have to be harder than the steel you are trying to burnish. Having said that, you can see that carbide would make the best burnisher, but for all but the very hardest HSS tool steel, the file metal would work.

My dad used to sharpen the high carbon blades in his "Red Devil" scrapers with a single cut file, then burnish the edge with a burnisher he had made from an old file. He was a hardwood floor finisher for over 50 years, and he scraped the ends of all the boards where the sander couldn't get to. He must have scraped hundreds of thousands of square feet of oak flooring in his lifetime.

Just thought of one more possibility if only one edge or side is ground smooth. I am a jeweler in my spare time an I sometimes grind the edge off a perfectly good file to make a "safe" edge. That is so I can file right up to a corner where I only want to cut one of the two surfaces.
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Bob, if the teeth were ground off of just one side it could have been a file that someone made safe on one side. In other words used when you had to file a surface up next to something that you didn't want to be damaged by the teeth on the edge. Other wise don't know what it was used for. I don't ever throw away any old files.
The file is about 8" long, teeth ground off both sides and there are 2 slight grooves where the file set on the tool rest to take the teeth off.

He was not a turner, just a amateur home builder. I think he build 4 or 5 houses.

Burnisher makes the most sense. As long as the scraper is in the vise, may saw well grab the toothless file to finish it up.

I did a little blacksmith work when I was in high school. Made a cold chisel. Not sure what ever happened to it.
I also made a chisel in high school (47 years ago). It is still my goto chisel for metal work - holds an edge better than any of the commercial ones.
I think mine was probably stolen along with the drill bit gauge I made. The price you pay for doing too good a job :))
If the edge or end is ground straight, it could have been used to flatten hand plane soles. Files are hard enough to use like a card scraper on cast or ductile iron, and were (are) used to scrape down the high spots. The end is used for narrow planes or to get the worst spots down. The edge is then used to finish the flattening across the sole. Also works on wood. Because it doesn't flex, you can scrape to a straight flat surface. If it doesn't scrape it may be worn on the edge.

Faster than using sandpaper, and widely used before sheets of abrasive paper and belt sanders were available.

Just a thought

I knew the guy for 25 years. Not hobby woodworker think he probably built cabinets for his houses, but nothing fancy, just a plywood door on a box. No drawer slides, just wood runners.

I doubt if he ever flattened a plane bottom.

Both sides are the same, parallel 8" radii where the teeth were. The edges are ground flat and straight. There is a small straight grind on the face to square up the edges.

There is the possibility that is is a failed attempt at making a scraper?

I'll try to post a picture latter tonight. gotta go now.
Here's a couple of pics;

Tool Wood Household hardware Electric blue Fashion accessory

Sleeve Grey Collar Denim Electric blue


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Really do not have a clue. Almost like he started to make a double edged knife. I'll bet those edges really ate up his grinding wheel, unless his intent was to dress the wheel flat and smooth.

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