How to Get Shell of Drilled-Out Bolt Out of Part

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SteveHGraham
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Mon Jan 12, 2015 10:55 pm

It looks like the only answer is to bore it out completely. I don't know why it's sticking to the bore. The metal should be peeling off by now.
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Harold_V
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by Harold_V » Mon Jan 12, 2015 11:00 pm

Pretty good chance the piece moved, resulting in galling. If so, you'll find evidence of that when (if) you can peel away what remains.

I'd suggest that you may enjoy success once you break through the wall in one place. Relocate the piece under the boring head, moving opposite the break-through (move just a thou or two), then take another pass with the boring head. Do this until you break through the opposite side of the remaining piece. Once you've split the piece, one of the remaining pieces is bound to release. If not, repeat, so your following cut is 90° to the others. With care, you can make four cuts and not disturb the original bore.

Harold
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SteveHGraham
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Tue Jan 13, 2015 10:04 am

I agree with you and John. I am thinking I should just use an end mill smaller than the bore. I have a long 5/8" mill, but it will contact the bore all around the circumference.
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SteveHGraham
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Tue Jan 13, 2015 10:22 am

Here's a question: if two steel parts are galled together, without rust, would a powerful hydraulic press separate them or just deform everything?
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Russ Hanscom
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by Russ Hanscom » Tue Jan 13, 2015 11:04 am

At this stage, the hydraulic press is not going to be a help - not enough left to press on if I understand the situation correctly. Better to continue with the boring operations

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SteveHGraham
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Tue Jan 13, 2015 11:34 am

It's just a general question. If a part is galled, is it like trying to push out something welded or brazed? That would be a bad idea.
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Rich_Carlstedt
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by Rich_Carlstedt » Tue Jan 13, 2015 12:36 pm

Boring is the best option at this point as Harold said

Rich

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ronm
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by ronm » Tue Jan 13, 2015 2:11 pm

SteveHGraham wrote:It's just a general question. If a part is galled, is it like trying to push out something welded or brazed? That would be a bad idea.
I've had to press apart transmission gears that were seized to the shaft. On a shaft about 1.5" dia., a band of galled metal 1/8" wide will take over 10, sometimes 20 tons to move...so yeah, it's like a weld... a really good weld. The galled metal is usually so hard a file won't touch it.

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SteveHGraham
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Tue Jan 13, 2015 3:27 pm

That explains a lot. I don't understand how this happened. The guy who gave me the part says it's supposed to move freely, so how could it be so tight it would seize? He says he's going to give me the replacement bolt tonight so I can measure it. Once I know what the part does, I will probably go through it with a 5/8" S&D bit and call it done.

Right now I have to be cautious because I have no idea what this thing does.

Here's something weird. The replacement bolt is brass.
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by PeteH » Tue Jan 13, 2015 3:58 pm

Sounds like they had enough service calls for this exact problem, that someone decided "let's make the replacements out of something that will drill/split/drive out more easily".

Of course introducing brass into the equation means that you might get electrolytic corrosion, so maybe it's not such a good idea after all.
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by Harold_V » Tue Jan 13, 2015 4:50 pm

SteveHGraham wrote:It's just a general question. If a part is galled, is it like trying to push out something welded or brazed? That would be a bad idea.
I had a very negative experience early in my learning curve. I was trying to fit a shaft to a hole. I inserted the shaft, which promptly galled. A hydraulic press was used to separate the two, resulting in total destruction of both components.

Once a surface galls, it doesn't typically separate cleanly. In my case, the area that galled fused, for lack of better description. A huge "trench" was plowed through both components as a result.

Although there may not be total fusion, you can look at galled items as having been (spot) welded together. They'll come apart only with considerable protest.

One can only assume that your situation is one of galling. If you can peel the remaining pieces from the bore, you'll discover if that was the case, or not.

Harold
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Re: How to Get Shell of Drilled-Out Bolt Out of Part

Post by SteveHGraham » Tue Jan 13, 2015 5:17 pm

Thanks, Harold. Good info.
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