Files & Filing Primer

[Frank Turley]

Yesterday, I was looking at Blacksmithing General Discussion with the topic "Thumbs up Thumbs down," and the conversation meandered and came to settle on files and filing. "Old and Rusty" opined that he might like to see something written on files and their use. So I wrote a whole bunch, and when I pressed POST NEW TOPIC, Iforgeiron was shut down and everything I wrote was expunged. So here I go again with a few ideas and tips.

I was not a man of tools when I started traveling with a farrier in the early 1960's. During the first week, I was moving my 14" horse rasp maybe 4" and I was rubbing it across the foot on the back stroke. My mentor, Al, said to me LOUDLY in front of the client, "I'm going to get you a xxxx finger nail file if that's all the farther you can move that thing!" That was my clue to use as much of the file length as you can on the cutting forward stroke and to lift on the return stroke. Since the teeth are cut an an angle, you're getting nowhere by applying pressure on the return stroke.

We often use the large horse rasp for hot rasping and hot filing. The reason is that it is faster than cold filing. If you're forging hot, you get to take advantage of the heat. You don't want to quench and then cold file, then reheat, when that could be a waste of time. A farrier is lucky to get 30 horses out of a rasp. After that many, he is staying under the horse longer to get the job done. Many smiths get used rasps from horseshoers. Using a new rasp on hot work will ruin it, and new ones are expensive.

On the reverse of the rasp cut, there is a coarse double cut file. This means that there are two diagonal cuts that criss cross each other. In file parlance, the first cut is the "upcut" and the second one is the "overcut." The "coarse" cut has to do with depth and spacing fo the cuts. Be aware that the double cut is not necessarily related to "second cut." Second cut is a measure of file coarseness. There are commonly four coarsenesses depending on tooth spacing and depth: Coarse; second cut; bastard; and fine.

When you get into the small Swiss files (needle files), I believe that they have a numbering system for coarseness and fineness. I use the smaller files for decorating door hardware and especially Hispanic styled chest hardware. The finials can be a little involved. Something we do on Colonial period hardware is "edge filing" to give designs along the edges of strap hinges, utensils, etc. It helps to use a filing jig in the vise. The jig holds the workpiece at an angle, so you don't hafta' get on your knees and file uphill. BOL Blacksmith depot sells such a tool; they call it a "chamfering vise." Three corner files and knife-files help with edge filing.

The subject of draw filing came up. It is used primarily for obtaining a plane surface. Hold the file at 90º to the workpiece. If you push, the handle is in the right hand and the toe of the file in the left, applying even pressure. When I teach this, beginners do not belive me. They are sure I meant 75º or 80º. But no, 90º. If you want to cut on the pull stroke, the handle will be in your left hand.

A tip about draw filing. I've found it helpful to stand up my drill press vise in my big vise, clamping the lower jaw. You can then hold the flat piece in the drill press vise.

In filing something rounding. you start on the side away from you. When you reach the top of the round, the file is horizontal. You finish the stroke going upward on your side of the round. Again, beginners think that surely I must jest. They are convinced that you start on the near side and go up and over to the far side. Not so.

If helps, I think, to keep the file clean by covering the teeth with talc, schoolroom chalk, or soapstone, before use. You can also use a file card. Some cards have a bristle brush opposite the wire teeth. The cleansing wires are ducked backward at an slight angle toward the handle. One's first impulse might be to pull the card across the file, but it should be pushed. Pulling it causes the wires to become distorted. Little so-called pins get stuck in the file's teeth and they can cause scratches on the work. A sharpened point on a 1/8" brazing rod is helpful in removing stubborn pins.

The shapes and lengths of files can be seen in the American catalogs of McMaster-Carr, MSC, and Travers Tool. There are some imported files in the marketplace, not all that good. Some are OK. When I was shoeing horses many years ago, I used a Simonds rasp. Nicholson still is a fairly good brand. Grobet imported files probably have the best reputation.

I got some of my info from Nicholson's old handout pamphlet, "File Filosophy." I also used "Metalwork Technology and Practice" by Ludwig.

I am eager to hear corrections and/or additions.

[SoCal Dave]

Thanks Frank> Once again you impress me on your knowledge and that you share it with others. Keep up the good work.

[bigfootnampa]

Well I agree with you about the Grobet files, they are hard to beat... expensive too though. I REALLY like Pferd files too. I consider them very nearly as nice as the Grobet at prices nearer to Nicholson.

I often drawfile at such an angle as to present the TEETH of my file at a 90 degree angle to the work (meaning that the file body is presented at a different angle). I especially like to use this filing technique when filing edges on card scrapers as it helps to get an even burr on both sides of the tool. I will also alter my angles of attack (whether draw or push filing) in some cases to bridge chatter marks or other irregularities in the surfaces... makes it easier to cut the high spots off.

I buy LOTS of files at flea markets, yard sales and antique stores. I clean them and sharpen and derust in vinegar and they are often nearly new. Shamefully a great many are only damaged by poor handling and rust... hardly used at all! I pay from 25 cents to about $2 for them... hard to beat that for a DEAL! I likely have 200+ files on hand. :)

[Tom Allyn]

I've been gathering files at estates sales lately. I've found some real nice ones.

[Tom Allyn]

Does vinegar work as well as battery acid? That's what Weygers suggests using. Do you use vinegar full strength?

[John B]

Hi Frank, Thanks for that, just a couple of additions to what you have said on files, these are probably more specific to the engineers type files

New files should be "Run in" on softer materials before being used on steels,

Files should be handled and stored (-and handled) with care preferably in a felt/fabric lined container to prevent damage to the teeth's edges

Always use them with a handle (controversially the best use ever for a golf ball)

[Old N Rusty]

Thank you Frank, so much to learn, so short a lifetime,

[Francis Trez Cole]

great info Frank thank you. My grand father tough me many many of the points you make

[bigfootnampa]

I've never used battery acid so I couldn't compare... but vinegar works well and is cheap and not too dangerous. I do use it full strength, just household vinegar though so it is drinkable if you were desperate. 18 to 30 hours for most files with a couple of brushing and flipping sessions does the trick. Rinse and dry quickly and treat with oil immediately afterward! I use WD-40 sprayed on.

[Willis]

I also pick up a lot of files at flea markets and junk shops. I look specificaly for Nicholson or Black Diamond. I believe Nicholson bought out Black Diamond in the 50' or 60's as I sometimes find both names on the same file. I have over 50+ files on hand including my swiss files. I use an old yard rake head for a tool rack. The kind with the long teeth. For file handles I use dried corn cobbs. The cobb provides a relatively soft but nonslip grip and is a great insulator for hot filing. I just hang my files in the spaces between the rake tines. This keeps them seperated and I can tell at a glance if a file is out of place or missing. If you want you can stabalize the cobb by soaking overnight in a 50/50 mix of acetone and polyurathane varnish then stabb them onto a finishing nail drive into an out of the way spot and let dry for 3-4 days. Once stabalized you can use the cobb just like wood. I've even made knife handles out of them and a fried actually turned a ball point pen out of one. I've done enough filing to realize that it can be an art form all on its own as evadenced by the many fine blades that I've seen by folks on here.

[KST1-Derek Fultz]

Willis, the corn cob thing is interesting. I might have to give that a try. Lord knows, there's a bunch of corn around here!

-Derek

[MattBower]

I recently posted this in antoher thread, but I'll repost since it's relevant to this topic:

Nicholson Guide to Files and Filing.

Alexander Weygers recommends using the edge of a sheet of thin brass in place of a file card. You run it parallel to the file teeth and it conforms to the shape of the teeth, gets down into the grooves, and does a very good job of lifting out pins. The brass won't damage the files' teeth, while hard steel wire file cards can. This is the larger-scale version of the sharpened brazing rod that Frank mentioned.

On the issue of sharpening, I have used muriatic followed by a very thorough neutralization in a boiling, saturated solution of baking soda or washing soda. It definitely improved the sharpness of the files. I've heard it said never to use muriatic on steel because the chlorine will permanently infiltrate the steel or some such. I don't believe that, at least with respect to low alloy steels. It does not correspond to my own experience, and I'd note that muriatic is widely used for pickling in the steel industry. The steel your file was made from was likely pickled with HCl before it was turned into a file. I mention this not because I have any special love of muriatic, but because it's very easy to get.

As an alternative to acid sharpening, I have heard nothing but good things about this service. I have yet to use it myself, although I plan to give it a try when when enough of my files get dull. http://www.boggstool.com/

For those who aren't able to get out to a lot of yard/estate sales, you can often find batches of used files on eBay for not lot of money. Many look like they've seen better days, but many of those can probably be resurrected by sharpening. The ones that can't be saved will make good tools and knives. I got a well cared-for set of six, 6"-8" Grobet Swiss pattern, fine-cut files on eBay for about $30, including shipping. I'm very pleased with them.

[Tom Allyn]

I posted this in another thread but that post and image disappeared. Maybe it was deemed off-topic in that thread. Anyway, here's an image of a knife tang I filed back in June. By carefully checking my work both by eye and with a micrometer I was able to achieve a tolerance of +/- 1/100".

Will anyone else share images of their filing work?

[Dodge]

For my power hammer, I used a slug cut from 3" plate. to make the corners more true, I welded 1" angle to them and then filed smooth. Draw filing was tedious at first, breaking through the mill-scaled surface but without the aide of a actual mill....

[ThomasPowers]

Mill scale is hard on files, abrasive or chemical clean off of mill scale is suggested before going at it with a file.

The old black diamond files, pre Nicholson, were 1.2% C and so I amassed a bunch of them to beef up the end carbon content of pattern welded billets. (I would buy any at my buy point at the fleamarket in Columbus OH; so some dealers tried to raise the price on me only to find I would buy *none* above my buy point: zero elasticity of demand)

[beth]

thanks for the information frank and others - maybe its been a long day, but why when your filing a round shape do you start from the back not the front? i entirely take your word for it, im sure your right,but i cant work out why ! thanks for patience...... :)

[MattBower]

I meant to ask about that. I'm having a hard time envisioning it. It sounds extremely awkward.

[beth]

i can imagine doing it (although it feels more natural to start from the front which is what i do), but not why it would make a difference... ?? :unsure:

[Frank Turley]

In filing a rounding shape by starting on the side away from you, you're using the point (toe) of the file at a known, downward angle. When you're horizontal with the file, you're at the mid-point of the file length. Finishing the stroke uphill on your side at a known angle, you're at the heel of the file. You are using the full length of the file in a uniform manner with uniform pressure. When you go up and over starting from your side, you may be using only one small portion of the file length in a less controlled manner.

Using the full length of the file will give the workpiece a nicer, rounding appearance, and faster.

[MattBower]

So you're reaching over the work and drawing the filed toward yourself toe first, as though you were trying to commit seppuku?

[beth]

keep trying to thankyou for you r clear answer frank but it wont pop up! this is my third try!! :)

[beth]

by the way matt - is that you on the birthdays? happy birthday if it is many happy returns and all that stuff..

[Frank Turley]

MattBower,
You're being funny and/or obtuse? It's a pushed, cutting stroke.

[Francis Trez Cole]

I use an old golf ball as a handle on the file fits in the palm of you hand real nice. Just drill a hole in the ball and drive it on with a hammer. Cheep handles they have guys that go diving and clean out the ponds on the golf course.

[Tom Allyn]

... I welded 1" angle to them and then filed smooth.

Good looking piece of work, Dodge.