Years ago, decades ago, in the 60's I was thinking about my future and I checked out a book about either blacksmithing or gunsmithing. The author had a short section on making files. He kind of said, no one else would teach this but I think it is important. Well, I didn't go into gunsmithing or blacksmithing but the idea of making files appeals to me. I have downloaded a book on Nicholson files that discusses how they are/were made and I found a video on the net of one being cut. I'd like to find out the title of the book I read years ago. If anyone knows of whence I speak please let me know. If there are other references on cutting files by hand and tempering them I'd be interested in that also.

 

thanks in advance,

 

Bo T

http://www.liogier-france.fr/?lang=en

I love that video of the making of the files!

There were a couple members of either the old Artmetal list (now the Sandbox)  or theforge list who cut files. Eisenhower, as in President Eisenhower's name means Iron Hewer or iron cutter, "file maker."

 

The process is pretty basic, a long flat sharp cold chisel, single bevel as I recall, a hammer and a steel blank in a clamp like a shaving horse. Start at the end and work towards the tang. With experience a rhythm is struck that sets the spacing, depth and angle of the teeth.

 

That is about what I know of file cutting. I don't know how or when it's hardened, if they're tempered, even the grade of steel. I'' be following the thread though.

 

Frosty The Lucky.

I believe Alexander Weygers had a diagram of a jig for rasp making in his book on blacksmithing.  It seems like I read somewhere that a certain amount of imperfection generates a smoother finish.  

It looks like he's indexing the cutter against the last tooth he cut.  It's much faster than I'd have thought.

It is sort of a minute to learn, lifetime to master.

 

I am not swure the book you are talking about, was it the book by Nicholson himself?

 

I have a small shaper coming soon I will setup for doing some different file tooth patterns and experiments.

Here is an address showing the Google book on NIcholson files; http://www.evenfallstudios.com/woodworks_library/a_treatise_on_files_and_rasps_nicholson1878.pdf .

 

One gentleman posted about making a wood cutting float. He hand filed every tooth in that float. I think cutting them with a chisel would have made a better tooth and it would have been a lot faster. Anyway, I figured that anyone who learned how to cut and temper files would probably be the only one on the block who knew how to do it. Definitely worth the time acquiring the knowledge, making the tools, and developing the skill.

Sam, I am interested in what you figure out.

Look at Da Vinci's file cutting machine for a renaissance take on it or the depiction of it in the Hausbucher Nuremberger

 

I have a sneaking suspicion you could find it in Diderot's Encyclopedia too if you had the complete series.

WOW!

Dave

Oh forgot to mention that Theophilus has instructions on how to do it and how to heat treat it including how to protect/case harden the teeth while heat treating---Divers Arts written circa 1120 A.D.

I imagine molten lead was used for hardening. Or a coating and a muffle.

Had a quick look on Diderot encyclopedia with out luck.

Maybe someone with better French then me can find it.

Andrew

http://portail.atilf.fr/cgi-bin/search2e?title=&author=&class=&speech=&objtype=plate_group+&word=&CONJUNCT=PHRASE&PROXY=moins+de&DISTANCE=3&OUTPUT=conc&SYSTEM_DIR=%2Fvar%2Fartfla%2Fencyclopedie%2Ftextdata%2FIMAGE%2F

I imagine molten lead was used for hardening. Or a coating and a muffle.

Or molten lead could have been used for both. I think a coating and a muffle oven was probably used for the hardening and the molten lead for the tempering. I maybe should look at Nicholsons book again.

ha HA! I actually found what I was looking for this time :) a few good resources came up early this year RE file cutting, see this thread for some more info and some videos

 

 

in retrospect its the same video :) but there are a few additional links including a second vid.

Thanks Chinobi, the historical perspective about filecutters in Sheffield was a great read.

Or molten lead could have been used for both. I think a coating and a muffle oven was probably used for the hardening and the molten lead for the tempering. I maybe should look at Nicholsons book again.

 

Doubt it, lead melts at a much higher temperature then a file would be tempered at.

no thanks due to me, Mat shared it with us originally :) i just connected the dots

 

very cyclical nature on this forum if you keep your eyes open  :ph34r:

Doubt it, lead melts at a much higher temperature then a file would be tempered at.

You're right. The book on Nicholson files noted that they tempered the TANGs in lead, I missed that during the first read.

Some of this file making appears to be shrouded in secrets and mystery. We can somewhat understand the annealing and cold cutting of teeth. It gets trickier when we talk about heat treatment. There is the subject of a paste coating on the tool before heating and hardening. One source from the late 1800's said that the file is covered with powdered cows' hooves and other materials. Holford* in his book, talks about making a butcher steel and protecting the linear cuts with a mixture of one half wheat flour and one half salt made into a paste with water. The trick is then seeing the red hardening heat, unless the file is in a controlled molten bath. One wonders whether the paste gets "thrown" (removed) by the thermal shock of the quench. The French film shows a file holder with collars and shows quenching at an angle, tip first. We can guess that the holder slows the quench a little and helps prevent warping. The same film does not talk about any surface coating to protect the teeth from scaling and decarburizing. We can often see a heat rainbow on file tangs, even on those files purchased today.

 

The old crucible steel has probably been replaced with electric furnace steel. I would guess that nowadays a little chromium is added for edge holding enhancement. Purely a guess.

 

"The 20th Century Toolsmith and Steelworker" Henry Holford

 

Sayings and Cornpone

For all bronc riders:

"Take a deep seet, a short rein, and put a faraway look in your eyes."

I would venture to say chromium would not be added, as chromium carbides present would cause a very jagged edge under magnified view.

I am not so sure also the holder/fixture in which he placed the file before quenching was so much to slow down the  quench (as it was not preheated, nor was the connection very ridged or tight nor does it really have any mass) as to prevent warping.

 

No coating in the film due to the use of molten salts. Any coating, based on your citations, would seem to either A-purely protect from oxidation and decarburization, or B- protect from oxidation and or on a small scale maybe carburize and reverse or just break even any decarb.

 

Some of this file making appears to be shrouded in secrets and mystery. We can somewhat understand the annealing and cold cutting of teeth. It gets trickier when we talk about heat treatment. There is the subject of a paste coating on the tool before heating and hardening. One source from the late 1800's said that the file is covered with powdered cows' hooves and other materials. Holford* in his book, talks about making a butcher steel and protecting the linear cuts with a mixture of one half wheat flour and one half salt made into a paste with water. The trick is then seeing the red hardening heat, unless the file is in a controlled molten bath. One wonders whether the paste gets "thrown" (removed) by the thermal shock of the quench.  
"The 20th Century Toolsmith and Steelworker" Henry Holford
 
[

Most of these methods are using metal of the date of the publications, it was then common to harden steel with the Wheatflour and salt mixture plus water to make a paste.

The paste was made to allow the mixture to adhere to the steel, (NB in this case, steel is the material, and also the type of item being hardened.)

The steel is heated until warm enough to coat the metal by immersing it into the paste. It is then heated to cherry red and plunged into cold soft water.
If properly done the steel will come out with a beautiful clean white surface, reputedly it is the same method used to make stubb files.

Molten Lead and Tin mixtures were often used to control temperatures when tempering tools with cutting edges, the makeup of the tin/lead alloy allowing precise temperature control before the days of pyrometers and tempilsticks.

Thanks John B. You answered a lot of questions I had. Do you believe that a lead/tin alloy might have been used for tempering files?