Chain adjuster removal

[redline1968]

I’d drill it then use a Easy out.. this will grip the screw and help un screw it. ...Get at major auto parts store... However, It looks pretty solid in there and without heat you might have to drill it out completely and tap it. Still ...it might be trouble since some of the thread sizes are not the same for the old adjustable screws.

 

[kreika]

Like Catfish said in your other post, use Kroil. Keep applying for several day or even leave the drop out soaking in it. Good luck.

 

[TR6SC]

If all else fails, there is a broken stud extracting device called an EDM. It is an electronic metal eater that will chew away everything in its path (the shaft of the bolt) leaving only the crests of the threads. These will peel or tap out.
Google Gordon Engineering.

 

[A.S.BOLTNUT]

Go to any hardware store and get a easy out, they save alot of head aches.

 

[Archie Sturmer]

Agree with the rust busting products first; propane 2nd, reverse easy-out product 3rd, only because of tight space, at each end.
Summarizing: chemicals; heat; right tools; (and torque force).

Alternatively, you could dremel tool cut the front-end (protruding threads); making a much deeper slot at that end for your screwdriver (righty tighty and out the end which it came in).