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My summer hobby this year has been making knives from old files. Not surprising, I really enjoy it! Before starting, I did a lot of research on this forum and others about which file make the best knives. So I've picked up some old Simmonds, Nicholson USA and Black Diamond files at garage sales and ebay. After my first drilling attempt with a large bit (maybe 3/16 size) went off w/o a hitch, I broke it on my second file. Both were annealed, and duh, I wasn't using any oil. However, the subsequent 4 annealed files I tried drilling through dulled the bits very quickly. I thought that smaller would be better (less material to remove), so I had bought 1/8 and 3/32 bits from Home Cheapo and Lowes, the Milwaukee and the Irwin cobalt bits made for 'hard steel'. I went through 3 of them for one hole, lubing with 3-in-1.

The most success I've had recently was with Drill Hog, after reading several good reviews. However, I have already broken 3 of the 3/32 and just ordered the 1/8. On a whim, I put in a 3/16 bit from a box of random bits I got at an estate sale (the guy had machined parts for airplanes apparently). Adjusted my drill press for the appropriate torque, oiled up a spot the Drill Hog couldn't pass and viola, nailed it in about a minute.

For those of you who are making file knives, what brand of bits work for you? Do you find that smaller diameter works better over larger? I'd like to know what experiences you all have had. Thank you!

The pictures are of the second knife I made, with the 3 big holes being easy. The handle is some type of Indonesian hardwood (a hardwood deck company near me throws scraps out all the time) and the pins are from a clothes hanger.

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Edited by Aaron Hanenburg
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Normalizing gives a better structure for drilling than annealing does on 1095. Slow cooling it in a bucket of ashes gives a laminar anneal in which you get plates of carbides.  I use Irwin cobalts, they last well for me.  You may also be spot hardening the steel if your drill press is running too fast.  Set it as slow as it will go, and if you aren't making chips stop at once and hit it with a torch to a low red and let cool in still air.  If you didn't dull the bit it should work.

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Thank you for the response Alan! Hmmm, spot hardening makes sense. I'll get the bit to bite and then a few seconds later it stops chipping. I was following the instructions on the drill press and recommended RPM for the bit size. But tonight I'll slow it down :) 

From what I understand, normalizing is very similar to annealing. As a beginner, could you clarify the difference for me? Different sites have different answers and not very clear to me. The first files I ever tried to soften warped severely because I left them in a charcoal chimney for about 3 hours. I now have a small charcoal forge, but am still gun shy about leaving them in for too long. Right now I am getting them to non-magnetic and soaking for maybe 5-10 minutes. Then I bury them in playground sand over night. I've put some metal pieces in the mouth of the forge, so the file stays vertical to avoid the warp.

So, how long would you suggest keeping the file in to soak if kept above non-magnetic? And are you recommending an ash nap afterwards, or air cool? Thank you sir!

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If cobalt still doesn't work for you, go for solid carbide. They are expensive! But if used very carefully and only when needed they last a long time. I have a set of 3 or 4 that I know are the same size as the pins I like to use. 

I recommend http://www.carbideconnection.com/  I've had very good experience buying from them. I specifically recommend the "screw machine drills" as they are shorter and less prone to snapping. They will pretty much go through anything. 

Eric

Edited by Eric Dennis
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What I mean by normalizing is heating to just above critical, in this case 1425-1450 degrees F, or a medium reddish-orange in the dark, then allow to cool to black in still air without setting it down on anything.  Once there's no color showing in dim light you can put it on a firebrick or something to cool down completely.  1095 doesn't need a long soak at heat, a minute or less is fine, and I don't soak it at all.  Soak times are based on inches of thickness, and files are not thick, so there you go.

Sand is not the best thing to put stuff in, it's not really an insulator.  Ashes or lime are much better, if you're using a steel that responds to that kind of anneal like 5160.

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How fast are you trying to drill through? A lot of times only the slightest pressure will cut and won't ruin your bits as fast. I also run my drill press as slow as it goes. Forgive me if you already knew this. 

I buy the cheap "titanium" branded dewalt bits from lowes and they last me quite awhile.  (unless it's titanium I'm drilling, not related to the bit). 

 

Ps. I really like your knives and the Nicholson touch on the handle is awesome. 

Edited by Austin_Lyles
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1 hour ago, Eric Dennis said:

If cobalt still doesn't work for you, go for solid carbide. They are expensive! But if used very carefully and only when needed they last a long time. I have a set of 3 or 4 that I know are the same size as the pins I like to use. 

I recommend http://www.carbideconnection.com/  I've had very good experience buying from them. I specifically recommend the "screw machine drills" as they are shorter and less prone to snapping. They will pretty much go through anything. 

Eric

I tried a couple of carbide bits and yeah, they cut quick but broke. Luckily they were garage sale finds! Thanks for that suggestion, I'll check them out! What do you like to use for pins?

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52 minutes ago, Alan Longmire said:

What I mean by normalizing is heating to just above critical, in this case 1425-1450 degrees F, or a medium reddish-orange in the dark, then allow to cool to black in still air without setting it down on anything.  Once there's no color showing in dim light you can put it on a firebrick or something to cool down completely.  1095 doesn't need a long soak at heat, a minute or less is fine, and I don't soak it at all.  Soak times are based on inches of thickness, and files are not thick, so there you go.

Sand is not the best thing to put stuff in, it's not really an insulator.  Ashes or lime are much better, if you're using a steel that responds to that kind of anneal like 5160.

ahhh, ok. Thank you for clarifying for me. I have a bucket of ashes that I'll put it in and take it out of the fire quicker. Thanks Alan!

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53 minutes ago, Austin_Lyles said:

How fast are you trying to drill through? A lot of times only the slightest pressure will cut and won't ruin your bits as fast. I also run my drill press as slow as it goes. Forgive me if you already knew this. 

I buy the cheap "titanium" branded dewalt bits from lowes and they last me quite awhile.  (unless it's titanium I'm drilling, not related to the bit). 

 

Ps. I really like your knives and the that Nicholson touch on the handle is awesome. 

Whatever the top speed is on my Craftsman drill press is (like 3100RPM?) because I was using small bits 1/8 and under. I'd get a good bite and get a few hairs in then nothing. That would frustrate me, then I'd put a lot of pressure down, the bit would squeal in protest and I'd have to walk away. So i'm gonna go slow this evening, romance it a bit instead of wham bam take it ma'am:unsure:. Thanks for the compliment on the knife! I have some better looking ones coming up and will post them soon!

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For pins I generally use 1/8" or 3/16" brass rod or 5/16" diameter mosaic pins that I made. Sometimes I use steel rod if I feel I need a little more internal strength, but very rarely. 

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I have drilled hardened steel with a carbide tipped masonary bit! They are made with a 118* tip. Take your time and recut the carbide to 135* they will cut for a while before you spin the small carbide strips that are on them. An old machinist showed me that trick!!

I have also used spotting drill bits. They are very expensive and very hard. To  much pressure and the whole bit shatters. Take a look at this site: http://www.travers.com/spotting-drills/c/297807/  You can get them elsewhere I just used that site to show you what I was talking about!

Generally it is just easier and cheaper to anneal and reharden with the proper HT!!

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Well, I slowed down my drill press and that did the trick. Tried 5 or 6 different bits of various sizes and they all chomped through the files with ease. I feel like that was something basic to know or try, but I'm learning new things and grateful for everyone's knowledge and willingness to help!

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19 hours ago, Aaron Hanenburg said:

ahhh, ok. Thank you for clarifying for me. I have a bucket of ashes that I'll put it in and take it out of the fire quicker. Thanks Alan!

21 hours ago, Alan Longmire said:

Normalizing gives a better structure for drilling than annealing does on 1095. Slow cooling it in a bucket of ashes gives a laminar anneal in which you get plates of carbides.  I use Irwin cobalts, they last well for me.  You may also be spot hardening the steel if your drill press is running too fast.  Set it as slow as it will go, and if you aren't making chips stop at once and hit it with a torch to a low red and let cool in still air.  If you didn't dull the bit it should work.

20 hours ago, Alan Longmire said:

What I mean by normalizing is heating to just above critical, in this case 1425-1450 degrees F, or a medium reddish-orange in the dark, then allow to cool to black in still air without setting it down on anything.  Once there's no color showing in dim light you can put it on a firebrick or something to cool down completely.  1095 doesn't need a long soak at heat, a minute or less is fine, and I don't soak it at all.  Soak times are based on inches of thickness, and files are not thick, so there you go.

Aaron,

Revisit Alan's advice in his above posts. I used to go with the internet instructions I'd found and do the whole "24 hours in ashes" routine. Then I started normalizing. Heat a little above critical, hold it in still air until it cools to black (it can still be hot to touch; just no color left). Repeat, but this time a little less hot. Repeat a third time, again with slightly less heat than the second time.

Another helper is to be sure the scale is removed before drilling.

I routinely drill clean, normalized steel with Dewalt bits with no problem.

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1 hour ago, Don Abbott said:

Aaron,

Revisit Alan's advice in his above posts. I used to go with the internet instructions I'd found and do the whole "24 hours in ashes" routine. Then I started normalizing. Heat a little above critical, hold it in still air until it cools to black (it can still be hot to touch; just no color left). Repeat, but this time a little less hot. Repeat a third time, again with slightly less heat than the second time.

Another helper is to be sure the scale is removed before drilling.

I routinely drill clean, normalized steel with Dewalt bits with no problem.

Thank you Don, I'll try these methods on my next batch. I do use a 60 grit flap disc to remove the scale after they'be been in the fire before drilling and grinding

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