Tried drilling through my bk12 tonight, no go. Bit suggestions?

H

HotRodColt

Joined
Feb 28, 2007
Messages
330
Ordered some TKC scales a few weeks ago for my Bk12 and found out they dont fit because the holes for the weights put metal where the screws run through the TKC pieces. I was out at my grandparents shop tonight and worked up the nerver to go drill it out so I can install my scales. I found out the hard way all the bits in the shop are dull. Any suggestions on what type of drill bits I should use to drill through that heat treated steel? I didn't break or bend any, but they just wouldn't cut it.

I was trying to start with like a 3/32 or 1/8 in bit
 
i personally prefer cobalt drill bits for drilling steel - relatively cheap and holds up to the abuse, just make sure to keep things cool and well lubed
 
I've used Dewalt black oxide bits with good results, also heard carbide bits work well but are more expensive
 
Not sure on the bits, but a good quality cutting oil makes a world of difference. No matter what it's gonna be pretty tough to drill hardened steel. Just take it easy and use an actual cutting oil.
 
A center drill is a great thing to own..... It will get your bit started properly...... A little Tap Magic and any HighSpeed Steel(HSS) bit should be good, cobalt will last longer, carbide longer than that...... Center drills save a lot of projects......

E
 
Oh, and just to be clear on this.

Make sure you're drilling it from the side that DOESN'T turn it into a spinning BK12 Helicopter of death if something goes wrong. That way if the bit grabs and starts it turning somehow, you get bruises, instead of prosthetics :).
 
I am not sure what cutting oil grandpa has sitting next the the drill press, but it worked fine when I drilled a barrel for a pinned gas block on an AR.
 
Please post up some pics of the finished job. I'd be interested to see the outcome.
 
ocnLogan said:
Oh, and just to be clear on this.

Make sure you're drilling it from the side that DOESN'T turn it into a spinning BK12 Helicopter of death if something goes wrong. That way if the bit grabs and starts it turning somehow, you get bruises, instead of prosthetics :).
Click to expand...
Word!

Get into the habit of taping up that edge *anytime* you're working on a blade.
 
Not sure if you have access to a mill or if your drill press has different speeds but that makes all the difference. use carbide and the following: MCS X 4 divided by the tool diameter.
the material cutting speed (mcs) for a hard, heat treated steel will be about 60 so for example: if you have a 1/4" drill bit go 60 X 4 = 240 divided by 1/4" (.25) = 960 RPM on the Drill Press or mill.
use cutting oil if possible..an start with a center drill. it will slide right through it :)
 
ocnLogan said:
Oh, and just to be clear on this.

Make sure you're drilling it from the side that DOESN'T turn it into a spinning BK12 Helicopter of death if something goes wrong. That way if the bit grabs and starts it turning somehow, you get bruises, instead of prosthetics :).
Click to expand...

I want to live in a world where there are bk12 helicopters of death, don't kill my dreams!
 
orezona said:
LOL, this got me to laugh...

Good advice, though. I'm sure a few people have found out the hard way!
Click to expand...

I've got a nice scar on my left pinky knuckle that reminds me how vicious a BK9 whirling blade 'o death can be.
 
Clamp your work pieces. A nice sharp carbide bit should do the trick. Stepping the speed down a little may help also.
 
Just be prepared for this to be difficult. And echoing many others, clamp the blade and also use a stop block placed so that the rotation of the drill press forces the blade into the block. Clamps applied near the quill don't always hold well, but a long piece of wood clamped up against the blade should prevent any whirling BK12-o'death scenarios.
 
You must log in or register to reply here.
Back
Top