extracting broken screw from woodstove
Just as I was about to wrap up my annual maintenance on a Vermont Castings Encore woodstove, I realized that one of the screws holding the iron “hood” to the inside of one of the front doors had broken off, leaving a threaded portion of the screw left in the hole.
This is a fairly small diameter screw, maybe 3/16″ or so. What’s the best way to get that piece out of there without destroying the threads in the door?
Thanks.
Replies
It's called an "easyout" up here in Canada. It is a course left thread tapered thing. Can be gotten in many different sizes. Some as small as a #30 drill (1/8 inch drill). Just drill down the center of the hole then tap and turn the tool into the hole until the screw comes out.
CAUTION--- This is made of tooling steel---- Over torquing the screw extractor will break it in the hole and then you are "screwed"
Just use regular force and if it won't go then use bolt out or WD40 and soak it a while then try again.
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Probably your best bet here is a left-hand drill bit. These are designed for screw removal and usually will work better in small screws than will the traditional Easy-Outs.
Of course, in any event you must center-punch the broken screw first, to get the hole started right.
Maybe not the right way, but for a hole that small I would drill it out and tap it for a 1/4-20 and use a new screw
Jet is right. I'll just add a few things to his post. Use the drill size the manufactor of the EZ-Out recommends, center punch the screw so the drill bit dosen't wander. If the lube dosen't work try a little heat; one side only [ you want one side of the metal to expand, not both. Lots of luck.
If you end up messing up the threads, you can drill the whole thing out, rethread, and use a helicoil insert to regain the original threads.
Thanks for the tips everybody.I've used those reverse-threaded extractors before, although it's been awhile. Seems like I had mixed results. But I'll give it a shot. A little extra care at this stage probably will save time and headache in the long run.
"Easy Outs" have got to be the most misnamed thing in existance. Invariably they break, and now you're alot worse off: you have a piece of hardened steel in there now, that cannot be drilled.
I think the lefthand drill bits are the best, the trick is to locate the hole accurately; 'hard to do on the surface of a broken screw.
What's worked for me is to use first a Dremel with a small carbide cutter (this works to get out the broken piece of "Easy Out", too). I flatten the broken piece of screw, so I can accurately center-punch a point for the drill. Use a left-hand drill the size as the tap hole for the screw in question. if you are lucky the fragment will start to turn before you drill very much, but often the thing is so corroded in place that you just need to drill out most of it before it will come out. Then clean out the threads with a tap.
Use a dremel to flatten the screw. center punch a few times to "push" the screw in. Use the dremel again to cut a slot and agood fitting flat screw driver to remove. Use eazy outs one time and it snapped! real pig to remove!