Help with drilling out a stuck hex bolt

[GrowleyMonster]

Originally Posted by masonc

Grind a slot in the head with dremel or grinder with a cutting blade. You can put a large screwdriver in that and a wrench on the shaft to turn it

No need to do that unless the bolt head is rounded. No way for it to get rounded using the correct socket. What has happened is called "spalling", where dissimilar metals in a wet and electrolytic environment molecularly stick together. I am surprised an impact wrench did not budge it tho, or at least crack the aluminum.


I think its gonna take grinding off the bolt head, then drilling and tapping new holes to reinstall.

[boden36]

Set up a heat gun pointed at the casting and leave it running for an hour or so. Let the heat soak right through. This may expand things enough to allow you to loosen the bolt. Also try striking the head hard with a hammer.

[HopCar]

If you can heat the aluminum, the hole will expand breaking free from the stainless. I watched an outboard mechanic do that many times. He never had to drill one out.

When he put them back, he coated the threads with Permatex #3. They never stuck again.

[Dove1955]

Drilling out is the option if all else fails. Start with a drill bit slightly larger than the hole where the hex key goes in and drill until you reach the meat of the threaded stud. Then move to a larger diameter drill. This way your drilling stays centered. You will get to a point where there is just a thin layer of metal surrounding the edges where the socket for the hex key used to be. From there you can just lift the plate or whatever device the hex key was holding.

[bhillmail]

Before drilling, put the WD40 aside and try a can of PB Blaster penetrating catalyst. I fixed up a 70 Irwin that was on the hard for 13 years before I got it, and had all kinds of rusted bolts. Maybe I was extra lucky, but I didn't have to drill out one bolt. PB blaster worked like magic.

[drcat]

A few suggestions based on experience
1) if the SS bolt is in a horizontal position you'll want to soak in PB Blaster, but just spraying it does not work well. If the alum surface around it is large enough, try cutting a plastic cap ( like ones that come with a paint spray can) in half so it looks like a half moon. Glue the 1/2 cap onto the alum in a way that when you fill the 1/2 cap with PB Blaster, the bolt will be immersed in the liquid. Leave for a day , pry off the cap and see if the bolt will come off.
2) if you end up having to drill out the bolt, buy some LH drill bits, They drill going counter-clockwise so at least it is trying to unscrew the bolt while you are drilling. Regular drill bits are tightening the bolt while you are drilling

[skipmac]

Have fought this battle many times over the years and here's my experience.

1. NEVER use an EZ Out or similar screw extractor. They very occasionally work but 9 times out of 10 if you can't turn the head of the bolt the EZ Out will break off in the bolt. Since they are made of extremely hard steel you will then have to get a diamond or tungsten grinder bit and spend a hour or three cutting out the EZ Out. I will never again use one of these except maybe to get a broken screw out of wood or plastic but with metal, no.

2. Use PB Blaster or Kroil. Soak the bolt, heat it, tap the head of the bolt for several minutes, heat it, soak it, let it sit for a day, repeat, repeat, repeat.

3. If #2 doesn't work get it really hot. Use an oxy-acetylene torch with a very fine tip OR use the jumper cable trick. Attach the cables to a large battery, ground one cable to the frame or body of the steering, then touch the head of the bolt with the hot cable making a short circuit. Caution, this can be dangerous and there will be a big spark when you touch the bolt. Hold it on for several seconds and that bolt will be really hot. When cool enough not to spontaneously combust dowse again with PB Blaster. Let it sit and soak for a while then try one last time. If that doesn't work then it's time to drill it out.

DRILLS - Get a serious, high grade drill bit. On the recommendation of Mainesail I bought a set of Norseman bits. Expensive but they cut through stainless better than anything I've ever seen. As noted, very slow speed, high pressure on the bit and use cutting oil.

Good luck.

[GBR134]

I’m not sure if there’s any science here but I have had good success using my wife’s domestic steam cleaner on a direct ‘spray’ nozzle. Not only does it apply heat but the steam also appears to eat into the white offertory gunk that appears to bind the Ali and the S/S. When bored I stop and administer easing spray and keep returning till free.

[skipmac]

Originally Posted by sy_gilana

Use Chemistry...go Breaking Bad on it!


Make a saturated solution of Ammonium Aluminum Sulfate commonly called ALUM.


Heat it to about 180f drop the part in. The steel will dissolve. (Use an Aluminum pot)

Now this sounds extremely interesting. I always suspected there was some chemical that would react with ferrous metals but not Al or others but google found nothing in a couple of fairly extensive searches. Even asked a couple of friends in the chemical business but struck out there as well.

Thanks. This is going to a test the first chance I get.

[P3sailor]

First, there are products (penetrating oils) that work much better than WD-40. Aerokroil and MouseMilk are two that come to mind (spellings may be incorrect). But either of those applied in liberal amounts then add some good heat, may work but it sounds like you have a considerable amount of dissimilar metal corrosion going so this may not work.
Second, if you have no options other than drilling off the head, the rule of thumb is: low speed/high feed using plenty of cutting oil while doing so. Step drilling the bolts will ensure better control while drilling and make the job go more smoothly!
Third, I've had mixed results with easy-outs. The best I've found are/were available through Snap-On, most likely their Blue Point brand. If uncomfortable using the easy-outs, I would just drill the head off and, if practical, just drive the bolt shank out with a good punch and hammer.
Good luck to you on this.

[petter5]

First of all: I have been running a marina repair shop for more than 10 years and have handled hundreds of these so here's my 10 cents:


If it is possible to grab the end of the bolt with a wise grip plier and it also is possible to use a Tubo torch Mapp gas burner (link to e-bay: https://www.ebay.co.uk/itm/Mapp-Gas-...-/273088801597 )



Heat as much as possible and use the Wise grip plier to unscrew the bolt when it is as hot as possible. - The plier must not be heated, but used just after heating is "maximal"



If there is no stud left for fasten the plier it is possible to drill our the remaining bit of the bolt using a Left hand turning drill. These " special drill can be bought at well assorted tool shop's selling professional equipment. Start with a small drill, perfectly in the centre of the broken bolt. You must use a cutting fluid like "rocol" or similar to lubricate the drill - If no " rocol" is available, Mercruiser " High Performance gear oil " (this oil is green in colour) will do fine - you can purchase this oil in most mercury outlet's. Increase the size of the drill gradually. When the drill size increase, the broken stud will be heated by the rotating drill, and also the strength of the broken bolt will be weakened. Friction of the drill, combined with the generated heat produced and also combined with the lubricating oil used for the drill - and also the fact that you use a left hand rotating drill will if done properly, the broken bolt will release from the treads and unscrew by the force of the drill.


What ever, avoid conical screw extractors at ant cost - the newer work.

[arcticmonkey]

just reading impossible bolt removal... just finished doing "a drill out" on my 20 year old ranger.. at one point I took the bottom of the bolt off with a grinder
if underside is accessable shorten your bolt.. may save some agro

[abnt1]

As an auto mechanic I used to run into badly corroded fasteners, one method I used to use was to heat the structure the bolt was in and cool the bolt itself. Heat gun or a map gas torch and a can of compressed air
( upsidedown) should separate them..Heat the housing dont be shy and then cool the bolt as quickly as possible with out cooling the housing material, you may have to do it more than once , have good penetrating oil and a socket wrench at the ready, Good luck

[Jim Cate]

This seems like another place to extol the virtues of the ATF/acetone mix as penetrating oil. I'm a recent convert, and am continuously amazed at how well this inexpensive mix works!

Jim

[BB Bosun Mate]

what grade is the bolt you try to drill out? Stainless steel bolt mostly grade 5 and higher which mean it a paint in the rear to drill out. Have you try to tight it up a bit more and than loosen it? Or get a grinder and grind the head off first, remove the piece and soak in in diesel fuel or WD 40 over night, and I mean completely soak it not spray on (this always work for me when I was working as an auto mechanic)