Extracting broken drill bits - my method.

[Sodo]

PJ that was a GREAT link. The guy does not mention drilling thru the broken bolt to get penetrating oil to the other side, so I was able to pat myself on the back for having a tip he didn't mention. His description of welding to the broken bolt 5,8 diameters down was kind of exciting, hard-core wizardry that perhaps only guy did once, on one fairly well-behaved broken bolt and he's all stinkbones now can't talk to him.:laughing::laughing: Also he did NOT mention shattering the bit.

I like reading about stuff like that, inspiration for hardheads who don't give up. All the eqpt breaking down all over the world, some a mile underground or out at sea, or in a 3rd word country where spareparts come by pack animal,,, I enjoy repair stories. But how many of these mechanical wizards write them down and publish them?

 

[PJ The Kid]

LOL and to think I only posted the link for the 1 picture, hahaha. There is some good info, but it all needs to be taken with a grain of salt. Even advice given from people you trust, since it may have worked great for them in a certain situation on a certain type of metal at a certain temperature.

 

[BKBoiss]

Wow. I'm going to remember this, I have spent hours trying to "unscrew" a broken drill bit tip. I also got really good at welding nuts on broken bolts, when my Peterbilt was new we kept breaking control arm bolts, finally we changed them all after about number 5 or 6 and that solved the problem.

 

[alchemysa]

The key to breaking up the drill bit inside the hole is to have the right sort of 'punch'. You need a punch thats hard enough to break up the old drill bit. Nails and similar 'soft metal' items are no good. I've used old drill bit shanks (although of course they are brittle too). I've used bolts from masonry anchors. I think I've cut up old Allen Keys and used those in the past too. They are hard but don't break easily , and they come in just about every size you could want.

 

[Mysfyt]

Sometimes on larger bolts I will 'step' drill. That is, drill in about 3/16" with your pilot drill, then drill with the larger bit, rinse and repeat. This will lessen the possibility of breaking the pilot bit.

 

[JRobyn]

One of my favorite "cheap" punches is a concrete nail with the tip ground flat.

 

[drizler]

Instead of beating with a hammer next time try a pneumatic chisel . Use the pointed tip and hammer to your hearts content. It's usually the hammering that coaxes them into loosening anyways and 5000 BPM beats your hand method for most operations. Your hand will thank you with no carpal tunnel spasms.
WD 40, don't waste your money on that stuff. It's expensive and isn't worth much as a penetrant. Just save your old changed out ATF oil and mix it 50/50 with acetone. Costs peanuts and works as well as the best commercial brands.

 

[Cougsfan]

I have a couple sets of the HF left-hand bits. They are ok, but use them VERY cautiously! They are quite fragile compared to a good quality HSS bit.

I buy a lot of stuff at HF. But not drill bits. I had a 1/4 HF bit snap in two once under very moderate pressure while drilling a hole in a 2x4. I ended up drilling a hole in my other hand that was holding the wood. Never seen a bit break that easily.