I've got to remove a couple of bolts on a rear end that have broken off flush with the gasket surface of the cover. Remarkably I've never had a need for a set of bolt extractors until now. Can someone recommend a good set?

 

i have had much more luck with reverse rotation drill bits than i ever had with easyouts.
with me, 99% of the time the broken bolt undoes itself with the reverse rotation drill bit, and 99% of the time i use an easyout, the easyout breaks.

 

What tjc said- get a left-hand drill bit (and run your drill in reverse). A combination of heat and rust penetrant often help. We have a set of square easy-outs at work that seem better than the spiral ones, but I don't know where they came from. Don't drill the hole too big, otherwise the easy-out will expand the bolt when you drive it in, and make the bolt tighter.

 

The square ones are made by Proto, and they do work better than the spiral ones. Left hand drill bits work great for bolts. One thing I have learned since my machinist apprentiship in the Army, was that easy outs tend to work much better when the bolt is drilled out ......

1. as close to center as possible.

2. as large as possible.

Heating them with a torch and cooling them rapidly with water works really good for rusty bolts. With the hole drilled in the bolt the heat and rapid cooling helps to "draw" the bolt up, kinda like welding the i.d. of a really tight bearing race, it draws it up smaller and will come right out.

 

I have used the square E-Z outs with great success. They do not have the tendancy to expand the work piece like the spiral ones do. Proto makes good ones and they list what size drill to use on the tool itself. DO NOT try to skimp here. You get what you pay for. If you buy cheap ones they will break easily and then you are in worse hot water.

You also have to look at why the bolt broke in the first place then asses the best way to remove the broken part. If the head sheared off from lateral forces, or the bolt twisted off from over tightening, then you can probably remove it with the reverse drill method or the E-Z out and if your'e really lucky just try to rotate it out with a pick or small screwdriver first.
If the bolt broke because the threads seized, rusted or bottomed out on debris then you will have to use the drill and E-Z Out. Make sure you start the drill dead center so if the E-Z Out does not work, and you have to drill the remaining part of the bolt out you can follow with the right size tap and clean the threads out. This way can be successful if you just take your time and do not force anything.

Good Luck
Steve

 

Great advise, you have to take what it gives you.

 

I have lots of different types from all different names on them even though Hanson makes most of them for Snap On and Mac. I have the short spiral ones, the straight flute style, and the some other style for hard to reach broken bolts. I personally like the straight flute because I can work the fastner back and forth. Lots of heat and patience is the best way and if at all possible drill it out before you put heat to it because they get tougher to drill once you heat them.

 

I *finally* managed to get the bolt out. It took drilling out most of the center of the bolt, then using an easy-out to remove what was left of it. Fortunately it didn't bugger up the threads too much. I ran a tap down the hole to clean up the threads and everything seems to be good to go now.

The only place locally I could find left-hand drill bits was at Northern Tool and they only had them in a full set for about $50. I doubt that in this case it would have done any good. It took drilling out most of the bolt before it would finally come out.

 

Glade to hear you got it out, some times can really be a B>tch