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stereo.pete
05-07-2013, 08:33 PM
Quick question for you pros out there, I started drilling pin holes and a lanyard loop hole in my next knife. For the lanyard loop I started with an 1/8th inch pilot hole and then when I went to drill through that with a 1/4" bit I snapped the bit off and I have two huge burrs sticking out. Two questions, 1: What did I do wrong and 2: what can I do to fix this?


http://imageshack.us/a/img580/8383/wip22o.jpg

GlassEye
05-07-2013, 08:37 PM
Looks like you need to go slower. Were you using a press or hand-held drill?

stereo.pete
05-07-2013, 08:43 PM
Hand-held drill (no press at the moment) and I started slow but the bit wasn't moving at all so I slowly increased speed and then it snapped.

ajhuff
05-07-2013, 10:16 PM
Looks like you have quite a bit of the bit sticking out? It's hard for me to see in the picture. If so, clamp on it with some vice grips, use a propane torch and heat up the steel around (before you ask, no not that hot). Back it out by hand. Avoid any thing called an e-z-out at all costs. Next time, slow speed, slow pressure, use a lube. I like the wax like stuff. Maybe consider getting a drill press stand that accepts a hand drill. Not that expensive and cheaper than a drill press if funds are low.

-AJ

stereo.pete
05-07-2013, 10:26 PM
Looks like you have quite a bit of the bit sticking out? It's hard for me to see in the picture. If so, clamp on it with some vice grips, use a propane torch and heat up the steel around (before you ask, no not that hot). Back it out by hand. Avoid any thing called an e-z-out at all costs. Next time, slow speed, slow pressure, use a lube. I like the wax like stuff. Maybe consider getting a drill press stand that accepts a hand drill. Not that expensive and cheaper than a drill press if funds are low.

-AJ

AJ, the burr sticking out is actually the metal from the knife blank. The bit came out nice and clean, I may just have to cut that end off and and abandon the lanyard hole. Great idea for a drill press stand, I will start looking for one.

psfred
05-07-2013, 10:45 PM
What type of steel? If it's something that work hardens, you must use a good, sharp high speed steel bit, slow speed drill, and lubricant. A hand held drill will be WAY too fast unless you have a very old one that has gear reduction (WWII vintage). A drill press is a much better tool for this job, as you can slow it down properly.

Standard drill bits don't do what well in hard steel, and HSS bits are cheap enough.

Peter

DevinT
05-07-2013, 10:52 PM
Too much pressure and not enough speed. A little smaller pilot hole will also help.

Hoss

ajhuff
05-07-2013, 11:00 PM
I'm not a knife maker but I've wondered, why are you guys always high on HSS tool bits? I would go with cobalt. Why don't you guys use cobalt bits?

-AJ

DevinT
05-07-2013, 11:20 PM
Cobalt just means a better HSS with cobalt as one of the alloys. The brand or manufacture seems to make a bigger difference for me. There are also different grinds and spirals/flutes made for differing materials, matching the drill bit with the job and machine also helps.

Love and respect

Hoss

ajhuff
05-07-2013, 11:21 PM
Got it. Thanks.

-AJ

stereo.pete
05-08-2013, 02:28 AM
Thanks for the advice guys.

psfred
05-09-2013, 01:31 AM
High speed steels are alloys containing various amounts of tungsten, cobalt, manganese, vanadium, chromium, and other hard metals to make tools that will cut at high rotational and feed rates while remaining sharp. Some of them retain their hardness capabilities while running dull red heat, for instance. When drilling or machining hardened or work hardening steel, it's necessary to have a tool that remains harder than the material you are working -- just like trying to sharpen a RC 62 knife with a file, which is very likely softer than the knife, not gonna work well. HSS tools do not lose their hardness at the heat generated by the friction of the drill bit spinning on hard steel, unlike carbon steel bits, which then immediately become quite dull. From the looks of the chip, it appears that the steel in the knife blade as reached at least blue temperature, and likely somewhat higher. Bye bye carbon steel drill bit!

HSS drill bits are much cheaper now than they were some years ago, and are readily available. Carbon steel (blue) bits won't drill hardened knife steel well at all, they won't keep an edge long enough to get all the way through.

Peter

Stumblinman
05-09-2013, 08:25 AM
I'm a fan of step bits although not sure if this is the best for the application. Also a bit of cutting oil will help. I mainly work with mild steel though.

stereo.pete
05-09-2013, 12:47 PM
**Update: After taking everyone's advice into consideration, I had to go out and make a purchase that I knew would solve the problem. I purchased a tool that would handle the stress and pressure's of doing things the hard way.

Liquid Courage

http://imageshack.us/a/img402/8218/moarbeers.jpg


All jokes aside, I switched to a non-carbon drill bit (@psfred) and went at it with copious amounts of WD40 and steady hands.


http://imageshack.us/a/img23/8089/wip23.jpg


I was able to save the lanyard loop! Thanks everyone!

DevinT
05-09-2013, 09:37 PM
Pete, I tried to PM you and it said that you need to clear some space.

Hoss

stereo.pete
05-10-2013, 12:21 AM
Hoss,

I deleted a few PM's so I should have room now.