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Posted: Mon Jan 11, 2010 4:12 pm
by tom_k/mo
If you have it available, an EDM machine is MUCH better for removing broken bolts, etc... We use them in the aerospace industry. Imagine a titanium spar for a wing that costs upwards of $1M, and having a tap break off in a hole. You DON'T drill those out oversize or oblong. An EDM machine will burn the tap out without effecting the surrounding material. EDM machines can be found in most larger machine shops.
Posted: Mon Jan 11, 2010 4:38 pm
by heathicus
Thanks for the answer, guys! I'm not sure if the picture conveys it, but these that I have are pretty big. Around about 4" long or so. At least that seems big to me. So they must be for rather large bolts.
Posted: Mon Jan 11, 2010 5:25 pm
by colday
Yeah they look big.
And if you broke THAT bolt I want to see your forearms!
Posted: Mon Jan 11, 2010 5:27 pm
by lv2wdwrk
colday wrote:Yeah they look big.
And if you broke THAT bolt I want to see your forearms!
Or the length of your cheater bar.
Posted: Mon Jan 11, 2010 5:34 pm
by heathicus
colday wrote:Yeah they look big.
And if you broke THAT bolt I want to see your forearms!
Posted: Mon Jan 11, 2010 7:28 pm
by wlhayesmfs
I have a set of 4 in the wooden slide lid box they came in. I had them from my years 40 plus ago on the Railroad and they were used to remove pieces of broken pipe used in airlines used on power switches. I would not think of using this type of easyout on a broken bolt. But did work well on pipe. I guess my easyouts might have been a lot larger than most. Was for Pipe from 3/8" pipe to 2" pipe.
Posted: Mon Jan 11, 2010 9:08 pm
by horologist
I have only tried using these once with mixed results as well. Most of the screws I need to remove are too small for such things.
1. EDM is only as good as the operator, at work we had a guy who could remove the bolt and leave only a neat shell of the outside of the fastener and an undamaged hole. I think he is gone and the last guy managed to turn a 5/16" hole into a 1/2" plus canyon that nearly forced us to scrap a $250k main beam.
2. If your screw is in brass or copper you can disolve it with a concentrated solution of alum and water. A little heat accelerates the process. With this method the steel fastener boils away without damaging the surrounding metal. I doubt this would work well with aluminum though, too reactive. Try this on a scrap part first.
3. For accurately locating a hole you need to make a dimple with a punch at the correct location. A tool I have found to be quite handy for this task is:
http://www.leevalley.com/wood/page.aspx?c=2&p=45502&cat=1,42936,50298
Troy
Posted: Mon Jan 11, 2010 9:28 pm
by cocacola1012
That's nice if you have access to the broken screw/bolt.
Posted: Tue Jan 12, 2010 1:17 am
by ------------------------
Those are rather large. Kinda hard to tell with no comparison , but I think the top one is for removing broken 1/2'' threaded galvanized pipe. A broken nipple if you will:eek:
Posted: Tue Jan 12, 2010 1:19 am
by ------------------------
Those are rather large. Kinda hard to tell with no comparison , but I think the top one is for removing broken 1/2'' threaded galvanized pipe. A broken nipple if you will
