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Rivets are very soft. No special drill bits are required. Center punching the rivets and drilling straight and not getting into the trunnion on long rivets is much more important than the drill bit type. Drilling receiver holes on a hardened receiver (NDS etc.,) are a bit more tough. A better quality bit is needed. I have never had to use any titanium or highy specialized bits.
 

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Any drill bit you are likely to buy with a Ti coating is just to make up for crappy soft steel in the bit. Get a cobalt bit or even better a 2 flute carbide bit.

Start with a 1/8 or 9/64 to make sure you are on center then move up to 5/32 that will remove most of the rivet shank. Use a cold chisel to knock off the rivet head then punch the rivet out.

AK-builder sells great drill bits in the sizes you need.
 

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If there is a industrial machine supply house in your town go there. No shipping and I find bits are generally about $3 each for USA or German manufactured. Though those are getting more scarce. They alaso carry individual sized pin punches and the like vs buying things in sets which are 80% non useful for the purpose at hand.
 

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I use cheap sharp HSS bits from home depot. I find that when you inevitably break one, the cheaper they are, the easier they are to remove. I use a brand new 1/8,5/32 and 11/64 drill for each build, then I throw them away when I'm done. I have a really nice full drill set (every letter and both imperial and metric) I use for other jobs and I keep them sharp, but for doing a build, I use new cheap bits.
 

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I get all my bits from ENCO, go for the Carbide when you can, but HSS will do if the price bites you where you sit. For most applications you want "Screw Machine Drills" shorter and more stable. Buy 5 or 10 of each bit size you will need for the entire build. ENCO has constant promotions on shipping as well.
 

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IMO sharpness is way more important than hardness when it comes to this. Cobalt and the like will hold an edge longer, but when you snap one in a long rivet you'll be amazed at how hard it is to remove.
 

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m0ondoggy said:
IMO sharpness is way more important than hardness when it comes to this. Cobalt and the like will hold an edge longer, but when you snap one in a long rivet you'll be amazed at how hard it is to remove.
Say it ain't so moondoggy, I learned how to build AKs watching your videos. You just take the bit in your hand and hit it against the rivet a couple of times and it just disintegrates :grin:

Actually, as I'm sure you get a lot of, watching you video of that flawless demil and build then going out and doing one for myself I felt like a moron. Good to know that even you break bits on occasion.
 

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AKBLUE said:
Never encountered any hard rivets on an AK variant. They crush and drill rather easily by design.
The trunnion and receiver are hard and the barrel is of medium hardness in terms of drilling ease.
I have been drilling rivets out of AK's for 7-8 years and have demilled hundreds of kits. Rivets are soft until you crush them then they CAN get damn hard. They harden by design when crushed. They harden by the mechanial action of crushing. I drill out my cobalt drill bits with my carbide drill bits when they break. I almost never drill out the short rivets any more anyhow. I use an air hammer to cut the heads off then change bits to the pointed air hammer bit and hammer them out. I can remove all the short rivets with the air hammer in the time it takes to drill just one of them out. It leaves a perfect hole where the rivet was. Works great.
 

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Maybe the ak-builder ones aren't that great after all. I have drilled several rivets with them and about 3 NDS receivers. Well tonight, not one of then would go through my NDS-1. Time for new bits. They just stopped working all at once. Then they wouldn't even dent the receiver
 

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File flat, hit with 1/8" bit til almost through, then hit with a 1/4" to knock the head off and punch out the nub. I use cobalt bits for everything. I buy 12 at a time at a machinist supply shop.
 

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A nice set of drill bits and a drill doctor or some other sharpening method go hand in hand.
I scored a nice cobalt 115 piece US made drill set from enco for about $220 a couple of weeks ago.

It great, but I've still had to sharpen a couple of bits already. Thats just how it goes...
 

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has anyone tried using one of those drill bit sharpeners after a demill? Yeah, I know bits are cheap, but it feels wrong throwing out bits....
 

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grp said:
has anyone tried using one of those drill bit sharpeners after a demill? Yeah, I know bits are cheap, but it feels wrong throwing out bits....
My dad has a drill doctor and it works well. Do the math on how many cheap bits you have to throw out to amortize one.
 
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