How to tell if a file is sharp

Oct 21, 2003 13 Replies

Hello,



Can someone out there tell me how you tell if a file or rasp is sharp or if its ready to be scrapped. Picked up a couple handfulls of files and rasps at a garage sale and do not have enough experience to know if they are sharp enough. Is there a way to look at the edges of the grooves or something?



Thanks a bunch



Bob


Bob, those files can be sharpened. If you contact Steve Knight you can probably find out from him where he sends his files to be resharpened. IIRC he has NEW files sharpened before he uses them.

Steve knight

You might even want to look and buy a great hand plane from him... ;~)

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It used to be said that you could drip them in Nitric ACaid to sharpen them. It actually eats off the rounded off corners. A file often can be used on copper and non-ferrous when it can't be used on steel. Old rules:

1) Only use one file on one type of material-NEVER switch types of materials being filied with a file. 2) You can go from filing steel to copper/brass but not the reverse. 3) ALWAYS rub chalkboard chalk on a file before using it on aluminum, brass, copper, tin, lead, etc.. It fills in the gullets and allows you to take a card file and brush the chalk out and reuse it. 4) Never oil a file; it allows the steel to slide over the surface instead of cutting it; once it has slid, it is ruined. 5) Chalk and file and oil it. Keeps it from rusting. Just use a degreaser to clean it up BEFORE you try to use it.

I don't know...Probably so if you use them daily and have 15 or 20 that you go through.

as long as it is a good file it is. anymore I have them sharpened before I use them. the difference is pretty amazing. it is about 75% cheeper to get them resharpened. anymore new files are not sharp to begin with.

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a air compressor works well.

So does a file card. Thats what its made for. The comon wisdom was is to not use a wire brush as they are made with hardened steel. Of course, it natuaraly fallowes that people would start saying that about a file card do to their ignorance.

but you have to find one after you put it down (G) the air nozzle is faster and does a better job if you have good pressure.

It is also a good way to get sharp flecks of metal in your eyes, fine particulates in your lungs, or toxins into your bloodstream, if you aren't careful.

I could hardly believe it when I read that the anthrax at the Postal Sorting Centers went airborne because the workers used compressed air to clean the machinery. That has been verboten, for just that reason, for decades.

That's not to say Steve is not careful, just a few words of caution to all.

you do have a point. I never have to clean metal out just wood. and I always do it facing away. that's a easy lesson to learn (G)

Excellant point. I'd never thought of that although I use the air gun on everything off facing away from me. Have asthma so dust irritates lungs .

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