Broken Bolts

[Guest]

Once the head has snapped off a bolt, how do you get the rest of the bolt out without damaging the threads of the hole?

[Guest]

What I usually do is center drill the remaining piece of the bolt and use an Easy Out of the correct size, so that it won't snap also. Pre soak the bolt with Liquid Wrench or something similar.

[1937hd45]

Drill a hole DEAD CENTER in the bolt, starting with a center drill, start with a small drill and lots of cutting oil, progress up to larger drills. Then use an Easy-Out to remove the remails of the bolt. If the bolt is in an old aluminum casting you may not be so lucky. If you mess up the threads use a Heli-Coil to replace the threads.

[Ron Green]

Do all of the above but leave the oil soak in and tap it a few times ever so lighty to work the oil futher dowm into the threads.

[ronbarn]

Don't get angry, frustrated, or in a hurry and leave that darned Easy Out broken in the hole - that's really bad.<BR>Use the best penetrating oil you can find; let it soak for several days during which time you tap the broken end with a hammer and flat punch (as recommended above) and apply some heat with a torch, but not hot enough to melt or weld. Do all of this several times to get those threads penetrated.<P>Get a dead zero center accurate punch and the bolt. Start with the smallest drill you feel comfortable with, but make the first drilling fairly shallow. You do not want to have the drill bit bending and heading for the wall. As you increase size, increase depth. Don't use the easy out until you have as much of the bolt, hopefully without the threads removed. Remember to repeat the following sequence: penetrating oil - tapping - heating (repeat a few times) - drilling - repeating steps 1,2,3 - then easy out - all the time praying to whichever higher diety you prefer. Just don't break that Easy Out!!!<P>When all else fails you can use one of several brands of thread restoration. Good luck, and I, along with some of the others here will also say a prayer for you and your broken bolts. We've been there and done that.

[Guest]

The easiest way I found to get them out was to give the piece to my brother, the machinist. He takes it to work and brings it back the next day with the bolt out. No muss, no fuss!

[1937hd45]

Jeff, Where is this broken bolt? It may be quicker to just get replacement parts.

[Guest]

Try my old candle trick,after drilling the bolt out, heat the area with a torch and touch a wax candle to the bolt, the heat sucks the wax into the threads like sweating apipe joint now useyour easy out Works well !

[Guest]

Within the past 30 days, I believe, there was an excellent discussion on this subject on the Buick Club forum. If you can bring that up, there is a lot of worthwhile input on this problem. ~ hvs

[novaman]

Mike, good idea. I've been through all the other step before including removing that dang not so easy to get out easy out. I'll have to give that candle a try.

[Guest]

FYI -<BR>BCA DF thread on this subject: <A HREF="http://www.aaca.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=2&t=003305" TARGET=_blank>http://www.aaca.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=2&t=003305</A> <P>

[Guest]

I use left handed drill bits. They are exactly like drill bits but they turn the opposite direction to cut. They can only be found at industrial supply outlets, the hardware store does not have them. Don't buy cheap "M2" or Tiwan pink steel dime store tools, they won't last a single use.<P>Power drills turn too fast. I use an electric screw driver. The bolt always breaks at the most inacessable place. Start with a small piolet hole square in the center of the broken bolt. Then guestimate a drill bit smaller than the treads and go one size down. Go easy, when you reach the bottom of the piolet hole press hard. The bolt usually spins out. You still have one size left hand drill bit to try again, or the easy out if you prefer.

[Guest HOOIE]

My brother swears the candle trick works like magic.

[Guest]

I find the easiest way is to put a nut over the broken bolt and then use a wirefeed welder. Start at the bolt and weld until the nut is full of weld. You can then use a wrench to take it out as soon as the nut loses the redness caused by the heat of the weld.

[Guest]

Geez JoeF, I would never have thought of that!

[Guest]

Hmmm I've never heard of the candle trick before, I'll have to give that one a try.<P>This is the technique that I use on a regular basis and it has never failed me yet. MIG weld a nut to the broken bolt, allow to cool and remove. Don't use zinc plated nuts for this they won't weld properly, besides the fumes will kill you eventually. This works best on cast tapped holes because the MIG wire is mild steel and won't stick to the cast iron, otherwise you better be a good welder. Try this method before you use any petroleum lubricant as it will contaminate the weld.<P>If the bolt is broken below flush spot MIG weld up a projection until it is above the surface and perform the above procedure. If it doesn't come out the first time, repeat. Sometimes it takes a handfull of nuts before it will come out, but they always do.<P>If the offending fastener is a pipe plug, my favorite example is the plugs on lifter gallery oiling ports. These plugs are put in at the factory while the blocks are still hot with an impact gun. Heat the plug red hot with an acetylene torch, allow to cool and remove. They come out by hand after doing this a few times. <P>The worst fastener I ever had to remove was a full set of broken head bolts from a flat head engine that literally sat in a farmers field in a pond for the last 40 years. The bolts were hardened so drilling was out of the question, the MIG welding trick worked on every one. Mind you I must have used up 50-3/4" nuts getting them all out. The customer was amazed when I phoned him 2 hours later telling him the block was ready for pickup. <P>Here's my trick for getting out the cup on taper roller bearings. Stick weld a bead around the tapered cup face, there must be a continous bead around the entire face. The weld introduces a contraction strain that shrinks the cup. They literally fall out afterward, great for those places a slide hammer or puller won't reach. Of course you'll need a new cup.<p>[ 02-02-2002: Message edited by: Chuck da Machinist ]