O.K.

I have a problem. I bought a bunch of old rusty industrial bastard files from a local scrap yard (3 for a buck). According to Wayne Goddard, files such as these are made of W-1 or W-2 simple carbon steel and make fine blades when proper HT is done.

Well, I fired a couple up in the forge and shoved 'em in the kitchen oven for a few hours at steadily decreasing temps. I went out to the garage, profiles my blade with a cutoff wheel and a grindstone and started to drill holes for the pins.

First hole..., 1/4"..., butt end for thong tube, perfect.

Second hole..., 3/16"..., center of handle area..., one burnt carbide bit.

Third hole..., 1/8"..., forward handle area..., perfect.

O.K. I had a bad bit. Grabbed another 3/16" bit..., "SQEEEEEEAL!" Dead bit.

Digging for bits..., trip to Lowes..., hurry home..., re-anneal blade just to be sure..., another carbide bit meets its doom.

Find another bit, try to drill a 3/16" hole in ricasso area, killed the bit.

I've torched, forge heated, baked and screamed at this hunk of steel. What gives? I can't get it soft enough to drill in a few spots only.

HELP!

Andy

BTW They are Nicolson files.

My guess (and I'm far from an expert) is that you're cooling them too fast. W2 shouldn't cool any faster than 65 degree fahrenheit per hour. I think that is until you get under 1000 degrees, so you'd need to aneal for at least 7 hours, cooling at less than 65 degrees per hour.

Can you use some perlite or vermiculite? Perlite has been working well for me, it costs $3 for a bag at walmart and I just shove it in overnight. I take a hunk of scrap steel and heat it up first, shove it in to warm the stuff up a little bit and keep the heat in longer.

I just don't understand why some holes will drill and some won't. I even did some file work on the backbone with no resistance at all.

I thought about heating it and drilling why it was still cherry red, but I smell burning flesh already.

Perhaps I'll just bury the unfinished hole in the handle, and leave the half drilled "pothole" in the ricasso as an unintended design element. This blade is, after all, for me. I'll just use it as a reminder of the learning proccess.

Thanks for the info my friend. I'll head to Walmart today sometime for some Perlite. I'm guessing it will be in the 'lawn and garden' section. Do I put it in a oven or just shove the steel in a pan of this stuff (preheated as you say) and leave it in the garage? What are the specific mechanics?

Thanks again.

Andy

Carbides :( 1095 and W2 (steels that old files may be made from) are hyper-eutectoid, which simply means thay can have plenty leftover carbides and the higher above .83%C they get the more carbides you will get. A simple lamellar anneal (from critical to slow cool) will certainly free up and soften the main ferrite matrix, but you will get gobs of course carbides that will tend to want to pool together. You can drill fine in one spot (missing any carbide pockets) and then require a diamond bit in another area :( . Cycling the steel in that area, and finishing up with several sub critical heats should aleviate the problem (move that carbon around ;) ).

Look at the bright side, if you got this problem that means that it is indeed a hyper-eutectoid and not simply some case hardened material- another thing that old files could be made from ;) .

I don't know if you are doing this or not, but I'd strongly recommend you drill all your holes first with an 1/8" bit and come back with the larger size second. Drilling a pilot hole makes it a bit easier (pun intended).

Kevin,

Great info! That sure explains the problem.

BUT, I currently only use the stock removal method and cannot "move the carbon around".

I am going to try the Perlite method of annealing, which I purchased at Walmart today.

I will also try the 1/8" pilot hole that Mike suggests. Those carbide bits are gettin expensive!

The knife in question has since been heat treated with an edge quench in olive oil and final ground. The handle has been epoxied and has been setting up all night now.

The unfinished hole in the ricasso is a bold reminder of a lesson learned, and it may just wind up serving a purpose. This is to be a daily carry knife for me. I am planning a Kydex inside-the-pocket sheath. I think I'll form the Kydex real tight to the blade and use the 'divit' as sort of a 'snap'. This should allow a shorter sheath if it works out. I'll let ya' know.

Thanks for everything gents.

Andy :)

Kevin,

Great info! That sure explains the problem.

BUT, I currently only use the stock removal method and cannot "move the carbon around".

I am going to try the Perlite method of annealing, which I purchased at Walmart today...

That's fine, a hammer is not the way one moves carbon around, despite what too many mislead smiths may say ;) . You mentioned a torch in your above post, that is is the exact tool I would use to fix this problem, and I own quite a few forges. Carefully treat the area you wish to drill with a torch and you can disperse those carbides in about 5 minutes. Heating to critical and cooling in pearlite will, coincidentally, get you the steel microstructure "pearlite", which is lamellar and may continue to manifest this problem.

Keep a small jar of oil handy, torch the area to above ciritical (you should be able to hold the blade in your hand due to the localized heating) quench the area in the oil. Repeat to completely disolve the carbides, and then heat several times to a very dull reddish-black, the area will be as soft as one could possibly get it. It is important not to go over critical on the final heats, however.

Kevin,

Your knowledge is astounding.

I have a stack of files and will employ this method when I run into this problem in the future. Thanks a ton!

Andy

P.S. I have propane, mapp, or mapp/oxy capabilities. Which is best for this proceedure?

Mapp/Oxy= get it hot and get it done ;)