cutting files

[Leon]

Hello all, I'm new to this site and to building rifles. I've been working up the guts to ask this question so here goes. How do you cut files or other tools to fit specific jobs without ruining their integrity? I have an abrasive wheel chop saw, bench grinder and a 41/2 inch angle grinder with cutting capability.  Leon     

[albert]

If you can get your hands on a slow running "wet grinder" you can grind tools with not much trouble of taking the temper out of them. What I do sometimes at work I will have one of my co-workers cut tools down on a "Wire E.D.M."machine.

[Dphariss]

Grinder or belt sander or heat bend and reharden.
If you need something really strange a scraper might work better for metal or wood.
Dan

[Leon]

Thank you for the responses. I don't have any access to any special tools and I have cut enough metal with my abrasive tools to know they will heat up the the files quickly. I'll do it slowly with frequent cooling. I want to modify a knife edge file and a larger triangular file. My Lancaster kit is reaching the point were I have to make a decision as to how far I want to go with it. A wooden patch box and decorative carving seems daunting to me right now, but I'm willing to give a try. Thank you again. Leon   

[Acer Saccharum]

Even if you ruin the temper of a file by grinding, it will still cut wood very well.

You can also re-harden the files if you think it necessary. I'd try it out on wood before I went to any trouble.


These were made by cutting pieces off a file, and then brazed to steel shanks, then dunked in water while still hot. The final shapes were ground after the brazing.  Work pretty well, have not gotten dull, and I think it's pretty hard to damage the cutting teeth, unless you actually grind the teeth off.

[JCKelly]

Re-hardening a file offers a fine chance of ruining it. Nevertheless, here is how Nicholson heat treats/treated their 1095 files.
Heat 5 minutes at 1440F, quench in salt water. They heat in a lead pot, now a bismuth pot--impractical for home use. "Salt water" is water with about 13 ounces of table salt dissolved per gallon of water. Quench straight down, so maybe the thing will come out straight. Do not temper, use as-quenched for best hardness. Yes, it will be brittle. Just don't drop your files.
To keep the surface from loosing any carbon, probably easiest to buy a pound of "Non-Scaling Compound" from Brownells.
The way Nicholson did it, before EPA became unnecessarily concerned, was to first coat the file with "cyanide loaf". Really not as scary as it sounds, if you use exactly the right  chemical, i.e.  potassium ferrocyanide  K4Fe(CN)6
Mix the ferrocyanide (NOT ferricyanide) with flour and bone black, and boil the mix in salt water. No, I don't have proportions. Paint this onto the file you wish to harden. Either the cyanide loaf, or presumably Brownell's stuff, will keep from loosing carbon at the fine sharp tips of the file teeth. Cyanide loaf used to give a shallow but very hard surface to rasps, which were made of 1035 steel.
Or read Old Files and New Knives, Muzzle Blasts, some time in the 1980's, by James Kelly (metallurgist)
 

[D. Taylor Sapergia]

A very interesting treatise, Mr. Kelly.  Thanks.