Extracting broken bolt / screw

This method takes "a touch" that I don't have... got a lovely Studebaker exhaust manifold with a melted flange to show for trying it :( guess I need to find something consumable to practice on, but drilling really isn't so bad.

nate

Reply to
Nate Nagel
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Reply to
JR North

I have found that hitting the stub with a hammer, with or without a punch, as hard and as much as possible without destroying it often helps a great deal in freeing the bolt from the corrosion which locks it tight. If you can be lucky enough to drill the stub not quite all the way through, you can insert a punch into the hole and stretch the bottom of the stub. This will nearly always free it.

Don Young

Reply to
Don Young

I have used those extractors for about 55 years with very good results. They don't get them all out but I don't try any other type of extractor if the bolt is so tight that it has twisted off. Ridgid also sells the same type of extractor. I consider the tapered spiral extractors pretty useless. Some of the newer short spline extractors look pretty promising but I have not used them.

Don Young

Reply to
Don Young

Some bolts ain't gonna come out. Ever. For those, you may need to get creative about drilling and tapping another hole nearby.

When I twist off a fastener head, leaving a small stub sticking out, I have learned to NOT instantly grab the Vise-Grips. Because most of the time what happens when I do is that I crush the stub and it breaks off below the surface. Rather, I start with penetrating oil and I let it soak while I get out the MIG welder and cut up a piece of sheet steel about the size of a postage stamp as well as the No. 5 hand punch. I punch a hole in the sheet steel just large enough so the stub will fit through, then I use the MIG welder to weld the piece of sheet steel to the sheared-off fastener. Then I weld a nut to the piece of sheet steel, and use a wrench to gain a purchase. The combination of the penetrating oil, the heating/cooling of the welding, and the well-coupled torque via the welded nut will generally get it out if it's coming out.

If I shear off the nut/sheet steel, then I start thinking about alternative holes. If it's an aluminum workpiece and steel fastener, then I can get out the product called "Tap Out" (which I buy at my local machine shop supply and have never been able to find online) which is a kit containing material to build a dam and a solution which will dissolve the steel fastener.

If I'm going to try drilling down the axis of the stuck fastener, I'll use a left hand drill. I got a set of those in the easyout type kit I got from Craftsman. Of course, a left hand drill is rotating in the direction where if it binds up in the fastener the drill's torque might spin the fastener out.

But some fasteners ain't coming out. Ever. Get over it.

Grant

Reply to
Grant Erwin

Helicoils!

Reply to
gfretwell

Basically, Cobalt is the best, but you'll pay for it. Titanium is actually Titanium Nitride, which is a coating applied to regular HSS bits. Your best bet is to buy a complete screw extraction set from a quality manufacturer. In my autoshop, we do a lot of drilling out of all sorts of bolts, screws, and studs snapped off in engine blocks, rear axles, transmissions, and other parts. We have a set from Irwin with left hand cobalt drill bits from 1/16-1/2" by 1/64", 5 spiral screw extractors (the long ones that you use with a tap handle), and about 16 multispline extractors (the ones that are only about 1.5-2 diameters long, used with a 1/2" socket) New it cost about $250, but it has saved us thousands in scrapped parts.

As an aside, if you don't have a close quarters drill that can be reversed, you should buy one. I find that many of the bolts that are snapped off are that way specifically because they are in close quarters or are awkward to reach, and therefore were pulled from the side, bent, etc. I have a 3/8" air drill that's less than 3" wide (the chuck is at right angles to the body of the tool), but it can't reverse to use the left hand drill bits. I use a close quarters electric drill that is reversible for my LH bits.

Hope that helps

Reply to
woodworker88

What are you afraid of? It isn't neurosurgery. Harbor Freight has entry level MIG's at decent prices, and for the $$ you spend on one you'll save hours and hours of time that you would otherwise waste screwing around with drills, guide bushings 'easy (not) outs', busted taps and all the other hassles. Bill M is dead right on the technique. Personally, I have quite a few decades of auto repair work involving cylinder heads both high performance and stock. The oxyacetylene torch and the MIG rig are your friends, and you will find, as I did, that the time saving and quality of work is worth more than you realize. HTH

Joe

Reply to
Joe

Well ... first off -- they are *not* made of titanium, though some may list them as so made.

What those are are (hopefully) HSS or Cobalt steel coated with Titanium Nitride (TiN) for longer wear life.

I, personally, would go for the Cobalt steel, probably in screw machine length, and with split points.

I don't see the TiN coating being any help in this -- it is more of a help in production machining of specific materials. *And* -- it often is used to try to make people think that poor steel bits are better than they really are. You can get TiN coatings on both excellent steel and total junk steel. (With some experience, you may become able to tell the difference by sight in many cases.)

You'll be drilling tough bolts (thus the Cobalt steel) -- it is a bit better at cutting tough steels than plain HSS in my experience.

You'll probably be drilling with a hand held electric drill motor, so the split points will offer two benefits:

1) It will be easier to start the holes without the bits walking. 2) It will reduce the force which you will need to apply to drill through, making it easier to control the drill and keep it properly aligned with the hole.

Now the one thing which might argue for HSS instead of Cobalt steel is that for the smaller sizes, MSC wants to sell the bits in packages of

12, and in cobalt steel they get expensive rather rapidly. (It has been some time since I bought left-handed bits, but I recently bought some right-handed screw-machine length cobalts steel with split points to replace some lost out of an index of similar bits. (I found most of them on the floor, but about three seem to have run under the drill press and hidden with the swarf which has made its way there. :-( Anyway -- we were talking about $20.00 per size. -- Ouch!

No experience with the grabit. The usual broken screw extractors work sometimes -- but are more likely to break in the screw, leaving you with something even harder to drill out -- which will probably need solid carbide bits. :-)

Good Luck, DoN.

Reply to
DoN. Nichols

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This is (I think) the kind of engraving tool which has a carbide point in an adjustable vibrator Something like a "Burgess Vibro-Graver". You place the point on an area away from the center of the broken bolt, but not too close to the threads, and angle it so is is driving both down into the bolt and CCW. This is likely to get the bolt out -- though to be honest, I've never tried it.

I'll have to remember to try that next time I have that problem. :-)

Enjoy -- and now "Happy New Year", DoN.

Reply to
DoN. Nichols

What are you afraid of? It isn't neurosurgery. Harbor Freight has entry level MIG's at decent prices, and for the $$ you spend on one you'll save hours and hours of time that you would otherwise waste screwing around with drills, guide bushings 'easy (not) outs', busted taps and all the other hassles. Bill M is dead right on the technique. Personally, I have quite a few decades of auto repair work involving cylinder heads both high performance and stock. The oxyacetylene torch and the MIG rig are your friends, and you will find, as I did, that the time saving and quality of work is worth more than you realize. HTH

Joe

HF welders make good boat anchors. If you're serious about learning to weld, you can find a used Lincoln or Miller for the same price and have a REAL welder.

Steve

Reply to
SteveB

I have had several bolts break off flush, and could still be turned with just the point of an ice pick, or one of those little dental tools. A "buzzer" would impart a little force on there. Putting penetrant on there and leaving it sit surely wouldn't hurt. Critical points is that the threads are not boogered up, and that you put the point on the broken piece and keep it towards the center away from the threads. A lot of times, the break leaves a slight "shoulder" that the point can be pushed against.

Steve

Reply to
SteveB

In that case, what's the point of the vise grips?

This suggestion needs more explanation to make any sense to me -- if the bolt is so bound as to have caused it to twist off in place, seems unlikely this is going to work -- although I've no such engraving tool, either.

I'm the heat cycle kinda' guy, meself... :)

I do like the idea of the tack-weld a new nut on -- now if I only had a MIG or wire-feed unit instead of (or in addition to) the stick... :)

--

Reply to
dpb

Sometimes a bolt head will shear off because of sideways forces, and not be in the threads hard. Sometimes there is not enough sticking up to get a vise grip on there. I have had several that once you got it turned a couple of turns with an ice pick, you could get it the rest of the way out with your fingers.

They're all different.

Steve

Reply to
SteveB

Yup, I've done that many times, usually using a piece of hardened steel shaft (actually often a broken "knockout pin" from a cold heading machine, because that was the type of machinery I was working on) ground to a fine point on a bench grinder and a 3 lb. hammer. A nail might work in a pinch although you'll undoubtedly ruin it - the modified knockout punch was reusable, so I only had to make one every couple months or so. That only works on bolts that have broken due to fatigue or overtightening though, not ones that snapped when loosening due to threads being seized.

nate

Reply to
Nate Nagel

Who's to say the bolt broke because of torque?

Reply to
tnom

In this case stick is better than MIG. I do this a LOT (I'm the one that everybody brings jobs like this to) and MIG is only good if the bolt is already free. If the bolt isn't free then MIG makes to hard a deposit and the weld breaks before you can get any pressure. The best results are obtained with SS stick rod. Take a 3/32" stainless rod and with several small tacks build up a ball of stainless on top of the bolt. Then place a flat washer on there and weld it to the ball. Then take a nut and using a low flux rod (like 6011) weld it to the top of the above. That will give you the highest strength bond to the bolt you can get.

Reply to
Wayne Cook

Yes, Wayne, but I want to see you tacking to a #10 screw broken off

1/16" below the surface of an aluminum workpiece! You can with care shoot a .024 wire down there, though.

It depends entirely on what you're working on, of course. If you're working on oil field rigs or battleships, sure, stick would work great.

Grant

Reply to
Grant Erwin

I have 3 broken taps in aluminum that I need to get out.

Could someone please expand on this advice? "A hot alum solution will dissolve a steel screw without hurting the aluminum head. Eventually. It works better on taps"

So all I need to do is hop down to my local grocery store and buy some Alum, heat it up with water and let it sit over the broken taps?

Any other advice is appreciated. Since these are taps made of hardended metal I don't think I can drill them out. I thought about taking a dreml tool and a sand off disk to notch them and try to use a flat headed screw driver to extract them.

Thanks, Rolland

Reply to
re

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