10-24 broken bolt in expensive injection mold

[metron9]

Forgot to ask, exactly what brand of extractor are you referring too, do you have a link?

I took my truck to a guy that had some German made extractor for spark plugs that he was able to extract completely rusted off plugs with after I mucked it up trying to get them out with the dumb extractors. I would like to buy some good extractors.

 

[jmcvo]

10-24... Perhaps it's an aluminum insert?

It will not help your grief, but why in the world is a 10-24 in an expensive mold (as opposed to a 10-32)?

If the insert is steel, I agree; why 10-24? But if it's aluminum, 10-24 would be appropriate. (Aluminum is no longer used only for quick'n'dirty proto molds.)

Someone suggested 300-400° to kill red Loctite. IIRC, red (271, anyway) requires about 500°F to "kill" it. My last experience was removing scope base screws that some genius installed w/ red Loctite. Was successful but the pucker factor was right up there!

-jmcvo

 

[Motomoron]

What everyone else has said for sure. Weld on a nut if there's stick-out, left hand drill first, a little heat, square extractors only, etc.

But once the tap is broken off in the hole - and when it's say, absolutely, positively got to be done tomorrow morning:

Omegadrills!

OMEGADRILL

They really work, and the first time one saved an irreplaceable part that had to be in a different country in 24 hours - the set paid for itself about 150 times over.

Really, they're just micrograin carbide spade bits, but I think there may be something clever in the geometry of the pointy end.

In any case, I keep a set around for when...umm...other people need bailing out.

 

[John Garner]

metron9 --

In my 40-some years of experience removing an occasional broken bolt, I've concluded that broken-screw extractors are generally not a good idea. But for those times when a broken-screw extractor MUST be tried, my Number 1 choice is the spline-shaft-with-sliding-nut model sold by Ridgid Tool (the pipe wrench people). Here's a link to the first supplier a Google search turned up: 10 20 Piece Screw Extractor Set by Office Depot

(If I'm recalling correctly, PM participant wippin' boy works for the actual manufacturer of the splined-rod extractors, and has commented here that they are badged for a number of different "toolmakers", including the major tool-truck brand.)

I've found the square straight-taper extractors are 1) several steps down from the splined-rod type, and 2) several steps above the twisted-taper models.

In any case, and as others have pointed out, using a left-hand drill to drill the screw-extractor hole often eliminates the need to try the screw extractor.

John

 

[Boris]

I'm always amazed at people who break off bolts and think that for some reason a smaller diameter, more brittle tool will remove it. I'd set a nut on top and shoot a mig wire down through it, may take a few tries, but it's never failed me and doesn't take as much finesse as one might expect.

Then go to his shop and ask to see the extractors he used.....and thrown them the trash.

I was making an expensive fixture the other day and managed to break the tapping drill (2nd to last tool) in the thing.... too expensive to throw away all that work.
1 2.5mm dia carbide endmill, 2000 rpm and about 25mm/min feed soon had the remains of the drill out of the hole.
Until you've done it, you'll always think how can something that fragile get a bolt/drill/tap out of a part, and its not the fragility of the cutter, its the fact its harder than the thing you are drilling.

Had to get a broken torx screw out of a cutter body too... manual mill, locked spindle, 1500 rpm and wind it up slowly on the knee handle got that screw out and we were back running within 20 mins of the idot breaking the screw. (damned moron operator tightening it to 400 foot/pounds )

Boris

 

[bryan_machine]

+1 on Omegadrills - I've used them with success on several occasions.