Broke Bolt

[toonin22]

Anyone know the correct way to remove a corroded broken bolt. Tried heating it and easy out to no prevail, take any and all tips.

 

[partskenn]

Re: Broke Bolt

What do you have to work with? Is it busted off flush, or is a piece of the bolt sticking out still? Can you get to the back side of whatever you are working on. And did the easy out just not pull it out, or did you break it off in the bolt.

 

[toonin22]

Re: Broke Bolt

I have nothing to work with. And the easy out wouldn't turn it. And yes I can get to the back of it.

 

[Ned L]

Re: Broke Bolt

What kind of bolt, how big & what is it in? - Presuming steel bolt in steel or cast iron (engine). Considering you can get to the backside of the bolt (all the way through), if it were me, I would drill it to the tap size & chase the threads with a tap.
How close to 'on center' is your hole for the easy-out? If you are nicely on center then your best bet may be to drill it & chase the threads. Sometimes if you drill to the tap size you can carefully use a center punch to start to role the old remaining bolt threads into the center hole, which makes it much easier to find the original threads with the tap and chase the threads.

 

[rlb9844]

Re: Broke Bolt

If its a steel bolt in alluminum be careful drilling. I ruined a set of heads on my old outboard by the drill bit wandering off the bolt.

 

[dingbat]

Re: Broke Bolt

What is up with the back side access? I've drilled out more blind threaded holes than I care to remember back in my machinist days

Drill the center of the bolt out as large as you can. No need to get into the threads. Fill the hole with PB blaster and let sit for a couple of minutes. Take a sharp center punch and start at the top. Collapse the bolt inwards. Keep working the bolt with the center punch. It will come out. Needle nose pliers once you get it loose

 

[hungupthespikes]

Re: Broke Bolt

ATF-Acetone mix, 50-50 mix penetrating oil
http://www.kanolabs.com/msn/ more money, but works the best

http://www.sears.com/shc/s/p_10153_12605_SPM2156380901P?prdNo=18&blockNo=18&blockType=G18
You can find the square screw extractors cheaper that above.
The square ones work better than the spiral ones, the spiral extractors tend to push out on the bolt and make the threads even tighter. IMHO

 

[TestEngr]

Re: Broke Bolt

As others suggest, if you can get to the back side drill it out slightly smaller than the threads. *Most* of the time it will break loose just from the drilling. If not a small hamer and chisel will get whats left out.

Of course multiple shots of penetrating oil over the course of a couple days can work wonders.

Nothing can beat Kano Kroil penetrating oil.

 

[tswiczko]

Re: Broke Bolt

^^^^^^+1 on the Kroil.I bought a set of LH twist drill bits years ago for just such occasions if they are sharp they will usually grab when you get about half way through the bolt and turn it out. I don't know what type of metal you are in or what the bolt is made of but there are many approaches to removing a broken bolt, depends on the situation.

There are also many options if you damage the hole getting the old bolt out,(do you have to ask how I know:redface you can also drill to the next size up if you damage the threads, tap and insert a keensert heli-coil http://www.thorintl.com/Keenserts-Keyserts-Keylocking-Inserts.htm if you are in thin metal you can drill it out and use a thin wall fastener http://www.pemnet.com/fastening_products/atlas/index_new.html , or just drill it out and put a nut on the backside if it doesn't interfere with anything.

good luck

 

[cr2k]

Re: Broke Bolt

can you heat the alum. around the bolt? That should release it to the easy out.

 

[dockwrecker]

Re: Broke Bolt

+2 on left handed drill bits. Hard to find but well worth the investment. I usually center punch and drill the offending bolt with a drill dia. much smaller than the bolt. Let it sit with a proper penetrating solution and then go after it with the left handed bit slightly smaller than the internal thread dia. The trick is to drill completely through the bolt with the small bit first.

 

[toonin22]

Re: Broke Bolt

I started small drilled as close to center as possible working my way up. Kept spraying it. Then went to the back with one almost the exact size of the bolt and it came out. I should of checked where to disconnect the shift shaft on an old Johnson. Found it on here tho a little late. Thanks.