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What is the best bolt extractor made.

chas

Short answer:

The BEST is an Elox machine.

Long answer:

Still Elox. That is, if you can get the part out and carry it in to the shop and are willing to forego the joys of doing it yourself. I believe Elox is short for electronic oxidation. In any case, it is an electrical discharge machine that zaps a charge in to the broken bolt and vaporizes it leaving the surrounding metal untouched. Many good mechanics end up at an Elox place after they have broken an extractor or not gotten all of the screw out. They charge extra for a broken extractor left in the bolt.

I have also used a cutting torch or an oxidizing flame on a welding torch to burn out a steel stud in a cast iron block. And a plasma cutter.


There are several types of manual screw extractors.

The most familiar, often called an easy out, is both spiral and tapered. A hole is drilled in to the center of the remaining screw or bolt, and the extractor is placed in the hole, struck with a hammer and the screw is then backed out with a tap handle.


Another type, the straight flute, is square in cross section, is tapered, and has an undercut flute on each corner. Operation is the same, except that it does not wedge itself in tighter as you back it out. It requires that the hammer blow be just enough to make it bite but not enough to wedge the screw in tighter.

A reverse drill bit will often loosen the bolt, too, so it is best to drill the hole for the tapered extractor with a left hand bit, since you have to drill a hole, anyway.

Snap On/Blue Point makes a straight spiral extractor that is really good.

They also make a set that is round and not tapered, that comes with drill guides and drills. It is also really good, in that it does not expand the bolt at all.


Yet another type is the Drill-Out power extractor. It is a drill bit and extractor all in one tool. It is drilled into the screw CCW and after the drill goes in the extractor starts to grab and the screw is backed out.

My order of preference among them is Elox, Snap on straight untapered, Snap on spiral untapered, Drill-Out, straight tapered flute, and spiral tapered.

That is just one guy's opinion, however, as every situation is different, and individual skill affects results. I would say the Drill-Out is the most fool proof available to the driveway mechanic. I have seen fewer of them broken. The key to most of these is to get the hole drilled straight and on center. I often use a moto tool and a small stone to make the broken off end flat so as to get a good center punch dimple. When I feel like going overboard, I make up a drill guide that bolts to a couple of other bolt holes and use a center drill. That way the drill can't go on walkabout.

If you just want to remove a screw with a wallowed-out head, Snap On makes a nifty tool for that. I have had good luck on brass instrument screws with it.

Most importantly, buy only a quality name from a quality country. A broken off extractor becomes a bigger problem.


And soak well with PB Blaster for as long as you can before.





[This message has been edited by bill h (edited August 16, 2004).]

Thanks Bill

Chas

Charles,

Ditto everything Billh suggested, with emphasis on one little item......

When pilots bring in a stud or bolt extraction problem to us with a busted-off extractor already in-place, we simply quadruple the price as a "beginning estimate".....

China, Taiwan & Mexico may be great vacation spots, but their quality control for tool steel is still Third World...In my judgement, these products have only marine applications - They should all be used for boat anchors....

If you buy extractors (& drill bits), stay with top-end U.S., German or Swedish manufacturers.....